Two circuits in the same electrical box.

Hello, I live in an apartment and decided to replace the gfci outlet in the bathroom today because I noticed it was slightly warm to the touch, even though nothing had been plugged into it for a while. There is one electrical box in the bathroom with one switch for the fan/light and the one gfci outlet. Anyway, I turned on the light switch, then found the breaker which turned it off. Strangely, power to the outlet was still on… The outlet in the bathroom seems to be tied to outlets in the living room. So is this okay? Are you allowed to have a switch and a outlet from 2 different circuits in the same electrical box? (This isn’t the only weirdness with the electrical system in my apartment. They had an electrical outlet wired in parallel with a light switch. When I would plug something in, the light would go on dimly…)

Mr. Williams,

Please accept this with all due respect.

From your post it is very clear you are neither a qualified electrician nor the owner of the property. I would advise you to report your concerns to the later before making any alterations to their property and let them bring in someone qualified.

We just had 10/26/2008, 20+ occupants displaced from an apartment fire, early information said someone was trying to do electrical work in a panel in one unit at a local apartment complex, luckily no one was injured but all occupants lost everthing, 8 apartments are no longer habitable and will require total demolition and reconstruction.

As to the configuration this would depend on the circa of the wiring and the AHJ


As Berry stated…

And to answer your question, yes it is common. The plug is often on a dedicated bathroom circuit. Several bathroom, garage, outdoor outlets are on this same circuit. The switch is on a lighting circuit in most cases unless it goes to a light above a tub/shower.

Why would the location of the light change which circuit powered the light?

Lighting fixtures in wet areas are required to be GFCI protected in some instances (check your building code manuals).

Also the bathroom Recepticals require a separate 20 amp circuit as required by code.
I do not quote building code requirements, this is just reference to your question.

  1. Recessed cans do not need to be GFI protected over a shower/tub. If there is fixture assembly/fan, then it needs to be protected as required by the manufacturer.(which is one instance)

  2. Bathroom receptacles do not require a separate 20 amp ckt. The 20 amp ckt can feed an entire bathroom (including lights) if it supplies only that bathroom. Another scenario is having a separate 20 amp ckt supply the receptacle along with another receptacle in an adjacent bathroom while having the lights/fan on a different circuit.

Also Bryan, GFI’s tend to feel slightly warmer than a regular receptacle. This is due to the circuitry inside. If you feel that you don’t have the knowledge for this type of work, please find someone else who is comfortable with working around electricity. We are here to help promote safety and cannot be considered a DIY forum.


Thanks for your answers, that first problem has left me a bit worried about the wiring in my apartment. I’m happy to leave the work to the landlord, but maybe I should also hire an independent electrician to check things out and make sure there aren’t any other problems.

If you are just renting this place why should you lay out this cost?
Leave it to the landlord.

[quote=“jwicklander, post:6, topic:33062”]

  1. Recessed cans do not need to be GFI protected over a shower/tub. If there is fixture assembly/fan, then it needs to be protected as required by the manufacturer.(which is one instance)

This statement is not entirely correct. There is some distance requirements for the height of the fixtures, sealing, etc. However, everyone is on the right track when they lead you to defer to an electrician. I am a certified electrical inspector through the state fire marshal’s office, and I still defer it when doing a home inspection…hopefully that will help to show that I was not attempting to perform an “electrical” inspection, if required someday.

Remember, we all live in a litigation nation!!!

This is for fixture type. There is NO requirement for GFI protection unless the manufacturer specifies it.

I did not note anything wrong with you bathroom recep. given the info in your original post, but this appears to be a real issue and should be addressed by an electrician.

In addition to the safety concerns noted above, it is also not legal (in WA state and I believe many others) for you to work on the wiring system of a building that you don not own.