I'm rewiring a few bedrooms in my house and came across some interesting wiring on both of them:

The wire at the bottom is the power source and the wire at the top goes up to the light/fan.

  • Why would they pigtail the hot off the connected hot/neutral, and connect the neutral from the light/fan to the grounds?
  • Should I just cap the incoming wire how it is and run a new wire for the switch and not even mess with it?
  • 2
    If the line from the bottom really is the power source, your fuses / breakers would be tripping because the line is shorted. Jun 15, 2017 at 14:43
  • @TheEvilGreebo It is 100% the power source and no breakers are shorting...
    – jjj
    Jun 15, 2017 at 14:45
  • have you disconnected the lines and then confirmed that with a volt meter because I can't see how this circuit works if hot and neutral are shorted together like that. Jun 15, 2017 at 14:46
  • 8
    @TheEvilGreebo - As horrible the situation is in that electrical box it could be that "shorted white/black" pair is being used to conduct the hot line off to another electrical box. I would not be the least bit surprised to look in the wall and see that particular cover split and running off to two places. Of course anyone with any knowledge at all would be going OMG.
    – Michael Karas
    Jun 15, 2017 at 14:50
  • 6
    Hire an electrician immediately and then run screaming from the house until the wiring is gutted and redone correctly. Jun 15, 2017 at 14:53

5 Answers 5


The picture that you show indicates some very serious and dangerous wiring connections. This was clearly done by someone that had NO clue to proper wiring craft and codes.

Since you have found similar issues in two spots it leaves to question about how much the rest of the abode is wired in similar careless and dangerous way. I would recommend that you bring in someone who knows all things related to mains wiring and codes and perform a 100% survey of all your electrical wiring including all boxes, panels, lights, switches and outlets. Without doing a rigorous job of this you will have no idea how much risk you are dealing with before someone or something gets electrocuted or seriously damaged.

  • Thanks for the reply. I'm guessing the white connected to the hot is not actually being used as neutral and instead being another hot going somewhere else. I actually ran a new line to one of the boxes already just to be safe and capped the "bad line" the way it already was. I'm not overly concerned since the house is 40+ years old, but I am curious exactly where this goes.
    – jjj
    Jun 15, 2017 at 14:53
  • 9
    @jjj I'm just going to tack this on here, but the issue here isn't entirely that the house will just burn down any minute (although possible). More so that whoever did the wiring was ignorant of color coding and that a ground isn't actually a neutral. The accidents will come when (like now) this is messed with. Sure the house has stood for 40 some years, but one missed wire could bring it down. It'd be best to trace every line like this, fix the connections and relabel any whites being used as hots.
    – TFK
    Jun 15, 2017 at 15:40
  • 5
    @jjj - You have two options: Inspect it like Mike said. Or screw this back into the wall and never work on anything tied to the electric system in the entire house until you do. You opened the can of worms; now you get to do your whole house. #TheMoneyPit
    – Mazura
    Jun 16, 2017 at 0:45
  • I posted an update for everyone
    – jjj
    Jun 16, 2017 at 14:28
  • BTW - that might be less expensive than it sounds. After hearing some arcing from my breaker box, I had this service done, and it cost me $40 because I have a home warranty. This can prevent the whole place from burning down so be sure to check if you have some insurance that might cover it.
    – Jasmine
    Jun 16, 2017 at 18:49

First I thought he was working around a broken wire. Except he did it twice.

He just believes paralleling wires is a good idea. He's wrong.

Each wire provides a separate function, and each is important. But paralleling is bad even if you had an extra wire, for other reasons.

For each cable he surely did the same thing with both ends. So that means you need to follow those two cables upstream and downstream (to the lamp) and inspect there too.

All this needs to be corrected. If the house is full of it, it'll be a lot of work. You can do it if you're willing to get a book at the library and school up on wiring basics. (don't learn too little and end up making it worse, that's what he did!). You can hire an electrician but it's big dollars for not terribly hard work.

Since you can't fix the whole house at once, work with one cable at a time, and correct both ends of the same cable. If you can't clearly identify which cable is which, then do one circuit at a time, fix all its cables. You can tell what's on the same circuit because it lights up when the breaker is on, and turns off when the breaker is off.

In the meantime, this is a serious wiring hazard for so many reasons. I would at the least get some GFCI + AFCI breakers until it is fixed.

  • I actually think it's just these two rooms. I've replaced other switches/plugs in this house and they were wired correctly. Actually, I'll bet this was wired after the main wiring was done, the original wiring doesn't use any plastic caps for the grounds like this. I'm betting it's just these two rooms which have switches connected to the overhead lights. In the other BRs the switches run to plugs (I'm assuming that's the original state). I'm going to correct these two (already corrected one), and cap these bad lines.
    – jjj
    Jun 15, 2017 at 15:21
  • @jjj If a cable in the wall is known to be defective (has a broken wire inside the wall), then pull it out of the wall entirely, or at least snip all the wires off flush at the box entrance on both ends. It should not be used at all, not even for one wire, because what killed one wire surely nicked or exposed others. Jun 15, 2017 at 15:30
  • Yep, I know the correct wiring. Nothing appears to be broken. I wonder if that incoming power is from the nearby plug (going by my theory that the original wiring was the switch controlling a half-hot plug, like other rooms). I'm going to check that out in a bit.
    – jjj
    Jun 15, 2017 at 15:31
  • 3
    @jjj I'm confused whether the cable is defective or not. The mere act of nutting wires together like in the photo, does not cause the cable to become bad: if all three conductors are still good, feel free to un-nut and re-use. The only reason to doubt the cable is that the guy paralleled; sometimes when paralleling is done, it's because of a broken wire in the cable. One broken wire condemns the whole cable. Jun 15, 2017 at 16:00
  • 2
    Adding GFCIs to a system like this is likely to just result in them tripping as soon as they are installed. Jun 15, 2017 at 18:56

One possible explanation.

The lower cable was originally a switch drop, with one wire of the lower cable being permanent hot and the other being switched hot. This sort of thing should be marked with tape/sleeving but things that should be marked don't always actually get marked.

At some point someone decided to change the switching arrangements, changing the previously switched connection to permanent on and adding a new switched light. So they connected the old permanent live and switched live together and connected them to one side of the new switch. They did not have a Neutral available at the box so they misused the Ground as a Neutral.

Another possibility as someone mentioned in the comments to another answer is that it was originally a bodged 3 way switching set-up and one of the switches was later removed.

Misuing the ground as a Neutral is bad for several reasons.

  1. If the ground becomes disconnected the load will drag it up to mains voltage.
  2. The ground wire may not be rated to carry regular operating currents. It is only intended to carry fault and leakage currents.
  3. Volt drop will cause small voltages to appear between different grounded items. While the voltage is low the potential currents are very high and can burn out things like signal wiring.

When you find crap like this, especially when you have found it more than once in the same installation IMO you really need to treat the entire installation as suspect. You really need to trace and map every wire so that you can check that the installation as a whole is sane.

On the plus side it at least looks like you have sheathed cables rather than single wires in conduit. That will likely make things easier to trace out.


Thanks everyone for all the input. I figured this out tonight, and it was as i suspected: a lazy half-hot outlet rewire.

Here is where the "bad" line originates:

I've confirmed:

  1. Upper-left line: incoming power
  2. Upper-right line: line to the switch (AKA the bad/paralleled line)
  3. Lower-right line: line that goes elsewhere and is not powered

This outlet has the tab broken, so it was originally a half-hot. I have actually rewired a room that was still half-hot in order to install a ceiling fan. Only when I rewired it, I put in a new duplex switch, and connected the neutrals back together so the line to the switch could be used to connect to a new line to the ceiling fan.

This bozo decided to not rewire anything at the outlet and instead capped and pigtailed the hot/neutral-acting-hot together as the power input to the switch, and ran the neutral/ground from the fan back down the ground wire.

All they really needed to do was move the neutral in the outlet box off the hot pigtails and onto a neutral pigtail (like I had previously done in another room), but for some reason they were either too lazy/didn't know what they were doing/thought running neutral to ground was OK.

Had I known this earlier I would've just fixed this outlet wiring like I did in the other room, but I'd already ran a new wire, so I just cut the bad wire at both ends and stuffed it in the wall. I imagine this is the same case in the other room where I found this (I will make sure to confirm before assuming 😀)

  • I'd say @Harper was right then. Double-hot legs
    – Machavity
    Jun 16, 2017 at 16:05
  • @NateBergeron I can't accept it within 24 hours, but I will. Thanks!
    – jjj
    Jun 16, 2017 at 17:46
  • 1
    Glad you figured it out, and I hope your audit of the remainder of your homes wiring doesn't turn up any other equally idiotic 'fixes' done by the same idiot as this one. Jun 16, 2017 at 18:18
  • @DanNeely (or anyone else) could I verify that I've corrected all of these right at the ground wire at the breaker box by disconnecting the ground wire and using a multimeter to check for voltage between the box and the ground wire? Any current would indicate there's still neutrals hooked to ground somewhere in the house, correct?
    – jjj
    Jun 16, 2017 at 21:01
  • I wouldn't mess with the ground wire of a live system w/o supervision. Disconnect the neutral, that's at least a little safer. Unload everything you can first. If you don't understand that last sentence, hire someone.
    – Mazura
    Jun 16, 2017 at 22:59

There's no way the wires at the bottom would be your power source. If it was, your hot and neutral are nutted together. That would cause an immediate trip of your circuit breaker. So I suspect the top wire is the power source.

It's obvious the ground is being improperly used as a neutral (this is a major shock risk the way it's wired). My bet is if you open the fan you'll find that the light and fan each use a wire. Someone probably had a double switch at one point and did it this way to avoid running 3-line wire.

Assuming you've got the fan and light on separate wires you can actually fix this easily.

  1. Take whatever is on the white wire off in the light fixture. Attack it to the black wire
  2. Disconnect the ground from the fixture's neutral and the neutral in the picture.
  3. Nut the ground off separately in the switch box and attach the ground to the fixture. Run a new ground wire to the switch (it looks like someone just cut it off previously!)
  4. Nut the white wires in the switch box together
  5. Remove the extra black wire between the switch and the nut and attach the black wire to the switch directly
  • I know it's hard to believe, but the bottom is 100% the power source. I'm positive, and have actually rewired one of these already. The top line goes directly to the light/fan and there's nothing else in the box. I ran a new line and capped the "bad line" the way it was.
    – jjj
    Jun 15, 2017 at 14:59
  • 2
    @jjj Then I'm with Michael at this point. Somewhere your ground is attached improperly to the neutral and you need an electrician to sort this out
    – Machavity
    Jun 15, 2017 at 15:00
  • Well it's not anymore since I rewired one of the rooms and disconnected that neutral and will do the same with the other room. That line is just capped now.
    – jjj
    Jun 15, 2017 at 15:01
  • 5
    @jjj wait. What? No. Each of those wires has a function, they're all needed. A circuit needs a neutral and you should not be misusing the bare as a neutral, thats for ground. If you mean you pulled another cable and are using the neutral from that cable, you must use the hot+neutral from the same cable, don't send hot up one cable and neutral up the other. If a cable has a broken wire, it has other damaged wires, take it out of service completely. Jun 15, 2017 at 15:20
  • 1
    Despite the totally incorrect wiring, could your feeder have originally been some sort of 3-way switch wiring (done improperly) with the black and white being carriers of the voltage and the ground wire functioning as common? That might at least explain why the white and black are now nutted together... Did you try and find the other end of that feed and see what's going on at the other end?
    – Milwrdfan
    Jun 15, 2017 at 17:54

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