I replaced an old light fixture over my kitchen sink with an LED light. Everything worked well. The switch beside the sink with a standard outlet in same box were old ( at least 40 years) also. I decided to replace the switch and put in a GFI outlet. 5 years ago had my fuses replaced by an electrician with a complete new breaker box. The breakers are mislabeled some I am not sure what they are supposed to say.

I located the breaker for the switch. It was off--no power to switch but the outlet was still live. Found that breaker shut it off. I took off the switch plate and to my amazement was a mass of wires. I carefully unraveled everything cleaned out the plaster from inside the box which is not attached to a 2x4. I reattached the wires as they had them to the new switch and outlet went to reset breakers the switch breaker reset the outlet would not. I already figured the GFI wouldn’t work until I figured out what all the wires were going to. I took out the GFI and put in a new standard outlet just to close it up until I could check what was on each breaker. I had flipped the breakers on so my main kitchen light would work. With better light I could see the light switch needed to go in more to put the plate on. As I barely touched the switch I heard the dreaded crack then darkness. I assumed I just shorted out the switch before I touched anything else I went to check both breakers were off. To my surprise 3 breakers were tripped. When examining my light switch and outlet it appears the ground wire touched the lower pole of the light switch.

I have tried replacing light switch and outlet with new still 3 breakers tripped here is a list of everything I have tried and still 3 breakers tripped.

  • Disconnected and capped all wires in box
  • Checked every switch and outlet involved in my house and garage to see if I could visualize and damages or issues that May trip a breaker.
  • I disconnected new light fixture the switch went to.
  • I looked in garage and basement to see if I could see anything suspicious with wires.

The switches and outlets that are involved are kind of random not in one location or group with others that are working in between. Could I possibly shorted out three separate breakers 2 x 15 amp. 1 x 20 amp. Also to note there are 4 sets of wires in box (1) RBW. (3) BW ground on all. I can give more details on wiring and what I have tried there if needed.

enter image description here

after taking off face plate pulled out slightly

after cleaning out and separating wires

  • 3
    Pictures of the wiring would be word at least 1000 words, usually more. Please see if you can edit some in using the "sun and mountains icon" above the edit box. If you have a picture you might have taken before changing the wiring, that would be very helpful.
    – Ecnerwal
    Commented Jan 28 at 2:04
  • This sounds to me like you're dealing with a multi-wire branch circuit. This was common for kitchen receptacles before GFCIs became code in the late 80s. I'm in a similar situation where I want to install GFCIs around the kitchen sink but I backed off when I realized there was more than 1 breaker involved. Here is some helpful reading while someone more knowledgeable than me helps you: 1. diy.stackexchange.com/questions/153510/… 2. diy.stackexchange.com/questions/71652/…
    – eszed
    Commented Jan 28 at 11:51
  • That receptacle in the first photo was installed wrong, so all assumptions are invalid. Commented Jan 30 at 3:30
  • I know it’s wrong that’s why I placed arrow. Oddly it has been working just fine for years. This is first time I was going to put in new light switch and GFI because it is next to sink. I cannot check which wires are hot because breakers are tripped.
    – Grandma 5
    Commented Jan 30 at 9:51
  • 1
    GFCI receptacle vs "standard" receptacle wiring are different. On the GFCI, there's a sticker covering the "LOAD" screws (some refer to that as the "for wizards only" sticker). Remove all wires from the LOAD screws and see if your receptacle works. Also, make sure that all your wires, especially grounds, are pushed to the back of the box were they're not likely to touch any other screws.
    – FreeMan
    Commented Jan 30 at 15:05

1 Answer 1


Like someone said, this likely is a shared neutral circuit (branch circuit), with multiple hots.

You just need to troubleshoot each one (the switch and the outlet). Turn off the breakers to both, and disconnect everything. Before you hook anything back up, I would check the voltage on each of the hots, going to each of the neutrals in that box. You should see 120V. Anything less, and you may have a three-way switch in there, or some connection isn't mechanically sound. I would also check voltage of each neutral to the ground. It should read 0. Again, if it doesn't, then you have a problem.

As for troubleshooting...with breakers off, hook both switch and outlet to the wires, but don't put them into the box.

  1. Turn on the breaker to the outlet, to see if it has 120V.

  2. Then turn off the outlet breaker, and turn on the breaker to the switch. See if it has 120V and/or the light works.

If they both work, then your problem is something is shorting out when you try to cram everything into the box. You could try taping around the entire switch, and around the outlet. That way, you are assured they aren't shorting out on each other when you push them in.

B) If they don't work, as in the breakers trip, then you may have wired things wrong.

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