I'd like to put a power outlet in a closet to power some tech. I have access to the attic above the closet so I'm looking for possible sources to tap into. I first thought about ceiling-mounted lights, but they're switched so I don't imagine I can get full-time power from them.

I do have hard-wired smoke detectors mounted in the ceiling, and they're on all the time. Can I tap into one of them to power the new outlet?

  • What circuit are the smoke detectors on? Apr 11, 2021 at 21:16
  • A regular household circuit (lights+outlets). No breakers are GFCI or AFCI.
    – Paul Price
    Apr 12, 2021 at 21:21

1 Answer 1


The National Building Code (NBC) -not the electrical code- requires that smoke alarm be permanently connected to a lighting circuit, or one that supplies both lighting and receptacles.

So if you have a junction box feeding a smoke detector, you can feed an outlet from there too. You will have to add a lighting circuit to it.

AFCI/GFCI circuits are permitted, and the alarm must have a battery backup.

Should you not have a GFCI/AFCI circuit, and should you require or want one, you could always use a GFCI/AFCI receptacle as your first outlet.

You can Leave the smoke alarm and the new lighting wired to the line side of the GFI outlet (e.g. branched off in a junction box leading to the outlet) and feed other receptacles from the protected side. Thus if you have a ground fault, you trip the outlets, but not the lighting and not the alarm.

It's wise to use lighting that will be used a lot, for instance main lighting for the new space. Often the master bedroom or kitchen is used (the choice depending on where you spend most of your leisure time). Don't use an obscure lighting spot, e.g. in a closet or a far corner, just to meet code.

  • Where does the GFCI come into this? Unless it's in a basement, the GFCI isn't needed... Apr 12, 2021 at 0:21
  • @ThreePhaseEel, correct, it was meant in case he needed a GFCI or required an AFCI. I'll edit
    – P2000
    Apr 12, 2021 at 0:52

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