I bought a house a few months ago. I own a refrigeration business and am very skilled with electrical. I discovered several things the electrician did that are extremely bizarre.

While I was checking out the panel, I went through each circuit labeling everything. There is one mystery single pole 20A breaker that I just can't seem to figure out. I pulled the panel cover off and there is a 12awg cable attached to it, yet nothing is without power when I turn it off. I've checked every outlet and fixture. I may have a line just laying live in the wall somewhere. I've left it off for now.

Anyone have any ideas on how I can trace this thing out?

  • 1
    outdoor, basement/crawlspace, or attic outlet perhaps?
    – Jasen
    Dec 21, 2023 at 3:54
  • Or a circuit no longer in use. It happens.
    – keshlam
    Dec 21, 2023 at 4:43
  • I edited for readability and removed a few things that seem to be irrelevant to the actual question as they just seemed distracting. Feel free to edit again if you think they're important to the question, but maybe indicate how they relate.
    – FreeMan
    Dec 21, 2023 at 13:10
  • Sump pump is the first thing that comes to my mind. My cousin in Canada did the same thing: turned of an apparently unused breaker and found 2 inches of water on his basement floor a week later. (He is originally from Europe from a region were sump pumps are totally unheard off. He had no idea they are very common (and needed) in North America.)
    – Tonny
    Dec 21, 2023 at 14:07
  • If it's an abandoned circuit in a wall, it's pointless to trace it now. Just leave the breaker off for a month, a year, and if you ever need the breaker for something else you can disconnect the wire, cap it and roll it up neatly in a corner of the panel. If you ever do to-the-studs renos of any room, keep an eye out for it.
    – jay613
    Dec 21, 2023 at 14:23

1 Answer 1


First, consider that there may be outside electric outlets, or wiring in place to prepare for installation of a new device, such as over-oven microwave, outdoor lighting, pool or well pump or an air conditioner.

However, there are various electric circuit tracers such as these, which can be used to follow an electric line. Some work by putting a small radio frequency (RF) generator at one end, and running an RF detector along the wall to detect RF leakage from the wire. Usually the generator plugs into an outlet, so one can find its breaker, but you would clip it on the breaker, to trace the wiring.

Rather than buy a tracer (those above range from ~US$40 to hundreds of dollars), you might find an electrician to loan you one... and you might need a new electrician to update that wiring, anyway.

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