I'm putting in a new switched ceiling outlet in a garage for ceiling shop lights. I want to have a 2-way switch to allow control from either side of the garage. For some reason the breaker trips if I connect the ground wire from the distal switch, but if I don't connect it to anything the outlet works as intended.

I'm wondering if this is normal? Am I wrong in leaving it disconnected? Is there a better way to wire this up?

Thanks in advance!

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  • Is it a GFCI or arc fault breaker? Or just a standard breaker?
    – Matthew
    Commented May 2 at 3:30
  • Please add photos of the wiring at your switches and outlets.
    – brhans
    Commented May 2 at 9:00
  • 2
    Yes to the answer below from Man…, and a reminder that the power to a receptacle has to be run in a cable (in the case of nm) or paired wire if in conduit. Plus, and I hate to sound harsh, but calling the switching a 2-way suggests that you need to do more reading before potentially burning down your house. Commented May 2 at 14:05
  • 1
    @Aloysius I should have called it a 3-way switch. I'm using NM cable.
    – GerryT
    Commented May 3 at 13:26
  • 1
    What you call it depends on where on the planet you are. In your (and my) part of the planet (based on outlet type) that's a 3-way - most of the rest of the world it's a 2-way (and the same thing happens with 4-way and 3-way.) On a global website this means you have to pay attention to location to use the right terms for what are really the same types of switches.
    – Ecnerwal
    Commented May 3 at 17:06

3 Answers 3


This diagram makes no sense as drawn. It is not clear how much of that is limitations in the drawing software vs. misunderstanding how 3-way switches are wired. Among other problems, I see: screws not connected to any wires; switched hot and neutral to receptacle(s) not together; multiple wires to individual screws. And it just doesn't seem "right" overall.

Here is a brief description of how to properly wire 3-way switches.


Connect all ground wires together. If metal boxes are used, the incoming ground goes to the box with a special screw and then the switch (assuming it has a metal yoke) grounds automatically. If plastic boxes are used then connect all grounds together with a pigtail to the switch ground screw. You do not include ground wires normally in wiring diagrams as they only add clutter.

3-Way Switch Screws

There is no standardization for the location of the 3-way switch screws. What is commonly done is to have two screws of one color (e.g., brass) and one screw of a different color (e.g., black). The two that are the same are used for the travelers, which are a pair of functionally identical wires that connect to the two screws on each switch. The screw that is different is the common, which can be:

  • Incoming Hot (i.e., from the breaker)
  • Outgoing Switched Hot (i.e., to the light or receptacle)

Wire Colors

Standard US 3-wire (not counting the ground - ground is always there, but is ignored for diagrams and instructions - just always connect all grounds together) cable is black/red/white. Neutral is always white, but white is not always neutral. However, if white is not used as neutral then it must be marked (usually a piece electrical tape - black or red or any color except green or white) on each end to indicate it is not neutral.

Neutral in Switch Boxes

Neutral is now required in switch boxes in most areas. I think (but am not 100% certain) there may be an exemption for a 3-way switch as long as at least one of the 3-way switches in a circuit has neutral. But when you are wiring a new circuit it is generally easy to wire it up so that neutral is everywhere.

Balanced Current

Cables running between boxes or wires inside conduit always need to be balanced to avoid certain problems. Ground doesn't count - it can take a different path as it only carries significant current in a short-term situation - so in a retrofit situation ground can be an entirely separate wire, though in normal installations it will always be either in the cable with other wires, in the conduit with other wires or be the conduit itself (metal conduit).

This can take a few forms, depending on the type of circuit:

  • Hot + Neutral
  • Switched Hot + Neutral
  • Hot + Travelers (at any time there is current on hot, one of the travelers is switched hot)
  • Switched Hot + Travelers (at any time there is current on switched hot, one of the travelers is hot)
  • Travelers + Neutral (at any time there is current on neutral, one of the travelers is switched hot) - this is what I recommend for a new 3-way switch circuit.
  • Hot + Switched Hot - this is an old-style switch loop, common in older houses but not allowed in newer code
  • Hot + Switched Hot + Neutral - this can either be switch loop + neutral to provide neutral in a switch box, or it can be switched circuit + hot to provide always-hot up to a switched fixture box to provide ongoing hot/neutral for another part of the circuit

How to Wire

I recommend a basic layout of:

  • Breaker -> Switch 1
  • Switch 1 -> Switch 2 (travelers + neutral)
  • Switch 2 -> Light

and here is how you do it:

  • Run a standard /2 (black/white) cable from the breaker to the Switch 1 box.

  • Switch 1 Box

    • black/white cable from breaker - black (hot) to common screw
    • black/white cable from breaker - white (neutral) to white (black/red/white cable)
    • black/red/white cable to switch 2 - black (traveler) to traveler screw
    • black/red/white cable to switch 2 - red (traveler) to traveler screw
  • Run the /3 (black/red/white) cable from Switch 1 box to Switch 2 box

  • Switch 2 Box

    • black/red/white cable from switch 1 - black (traveler) to traveler screw
    • black/red/white cable from switch 1 - red (traveler) to traveler screw
    • black/white cable to light - black (switched hot) to common screw
    • black/white cable to light - white (neutral) to white (black/red/white cable)
  • Run a standard /2 (black/white) cable from the Switch 2 box to the ceiling box

  • Ceiling Box

    • black/white cable from switch 2 - black (switched hot) to receptacle or light fixture hot screw
    • black/white cable from switch 2 - white (neutral) to receptacle or light fixture neutral screw

If you have more than one ceiling receptacle or light fixture, daisy-chain with additional /2 (black/white) cable.


You don't generally need GFCI protection on hardwired light fixtures. However, you do need GFCI protection on all receptacles in a garage. That can't be done using a GFCI/receptacle combination in the ceiling, so your options include:

  • GFCI/breaker
  • GFCI/receptacle in the circuit before the first of the 3-way switches
  • GFCI/receptacle in the circuit after the second of the 3-way switches - but I don't recommend that
  • GFCI/deadfront (same size as a receptacle but just has TEST/RESET buttons and no receptacle) before the first of the 3-way switches

Since most lighting uses relatively little power, I recommend a GFCI/receptacle. Having an extra receptacle right next to the first switch is convenient and also easy to do.

  • 1
    Thank you! My apologies for the rendering, I used Powerpoint as I didn't know how else to easily draw it out. I tried to depict the connections to screws by stopping lines near the receptacle terminals. Also didn't know not to draw ground lines. Also tried to learn how to do this via YouTube / Google so I tried to match the connections to what I was seeing. My apologies for not getting that figured out right, hence my ask here. Yes I have a GFCI as a source upstream, it is between the breaker and switch 1.
    – GerryT
    Commented May 2 at 13:10
  • @GerryT Not a problem. You're here to learn, and you worked with the tools you had. Commented May 2 at 14:18
  • 1
    @GerryT - In this case it makes sense to draw the grounds, since your breaker trips when you connect the ground.
    – Mark
    Commented May 2 at 15:26
  • 1
    @manassehkatz Just re-wired the whole thing per your instructions and it worked like a charm. Thx again!
    – GerryT
    Commented May 3 at 2:48

Always connect ground FIRST

Because when you don't, you create lies (a false narrative).

It is impossible for ground to break a circuit - unless it's already broken.

So the lie is "It breaks when I hook up ground therefore ground is the cause". Nope, the circuit has a serious problem that wasn't being detected because the safety ground wasn't there to catch it.

It's akin to telling the home inspector "yeah we don't have a radon detector because when we try to install them, they just beep incessantly".

So this question is totally barking up the wrong tree. You don't have a ground problem, you have a problem that grounding detects, which is its job. So now we should take a more careful look at your wiring, and the diagram you posted is not workable or accurate so please carefully review it against what is installed. And we can go from there.


I believe the problem is very simple, somewhere in the circuit there's a bare ground wire touching a hot wire. Inspect the new work carefully for where a ground wire could touch a live screw. I will routinely wrap outlets and switches in electrical tape to avoid this kind of problem. I recall there being some debate on this being wise, and I'd be open to comments on either side, but I know it's been working for me.

The bare copper ground wire might not be required for safety or meeting code but if by connecting a ground wire to a grounding screw you see a breaker trip then there is something wrong somewhere. That ground wire might be touching something live. There could be a defect or damage to an outlet or switch. Is this normal? No, absolutely not. Would it be wrong to leave the wire disconnected? That's something that maybe only a code inspector could answer.

  • 1
    "Would it be wrong to leave the wire disconnected?" is not up for inspector interpretation. The answer is "NO". Modern code (like from the 1980s onward) requires grounding at receptacles.
    – FreeMan
    Commented May 2 at 16:50
  • " requires grounding at receptacles " Is a ground wire required at the switch? I suspect so but I can see potential for exceptions to that rule. I'll emphasize my point that there is clearly something wrong because of this odd behavior, the question is if the easy path of leaving the ground wire to the switch disconnected would be a solution or potentially create more problems.
    – MacGuffin
    Commented May 2 at 16:58
  • 1
    Neutral is required at the switch (even if it doesn't connect to the switch - it's there for future smart switches). Grounding should be at the switch by default because you're either running NM-B (which has a ground) or wires through EMT (and the EMT should be grounded) or plastic conduit and you're pulling a ground because you'll need it at the point of use. I do believe that every switch I've seen in the last several years has a ground screw, so go ahead and attach it.
    – FreeMan
    Commented May 2 at 17:05
  • 1
    If there's a hot-to-ground short and your solution is "don't connect the ground wire" then you have a hot ground. That is completely unacceptable. And switches with metallic frames are required to be grounded.
    – Ecnerwal
    Commented May 3 at 17:00

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