I recently had my basement walls finished. I am not sure about this at all, but I do have a slight suspicion that one of my electrical receptacles might have been closed up behind the drywall. The room has an abundance of them, so that's not an issue, but I assume it's dangerous and illegal to have it closed up. I don't really want to pull down the wall just to check for this, especially since I'm probably just being paranoid and there is no receptacle. Is there any kind of tool or method for locating a receptacle behind drywall, just so I can be sure?

  • In the basement, is this all new construction, electric or just a redo of existing?
    – Jack
    Nov 5, 2016 at 2:03
  • @Jack - It previously had wall panels and old electric. I tore out the panels and had new electric put it along the framing so as to be grounded and support more receptacles. So it's essentially new electric on old framing, now covered by new drywall.
    – bubbleking
    Nov 5, 2016 at 2:06
  • I'm sure you've already learnt this lesson, but always take photos before drywall goes on! Its really handy to work out where studs are and where electrical goes.
    – Andrew
    Nov 8, 2016 at 17:51
  • @Andrew - Actually you just reminded me, I think my dad took one of those panorama photos when he was in town before the drywall. Good tip!
    – bubbleking
    Nov 8, 2016 at 17:53

2 Answers 2


The code states that the outlets need to be no farther apart than 12' and within 6' of a door. If you had more than what code required, that makes it a little more difficult. If you find one at the door then go 12' from there, literally measuring the wall length you should find one at every 12'. If you have a space larger than that you may have a covered receptacle. Your building plan should reflect this, referring to my comment about code requirement. Or it should show how many you have, if it has more than code would require. I presume the electrician had something to go by to reflect your needs.

With that out of the way, and you have a spot you suspect there is a covered receptacle there, use a straight edge, or anything with a straight edge that is 4' or maybe longer. Run it at the level you suspect where the outlet is and if there is a covered outlet, there will be a noticeable hump in the wall. For the screws will draw the drywall pretty well to the neighboring studs but obviously not so where the covered outlet is. If you find one, the highest spot will be the outlet.

  • Thanks. I'll give this a shot. I know approximately where it would be. I purposefully had them put in significantly more than just one receptacle every 12 feet, so the gap I'm looking at isn't even 12 feet, but there still might be a box back there. I know the height and I know where the studs are. I'll try the straight edge and let you know how it goes.
    – bubbleking
    Nov 5, 2016 at 3:23
  • If one is covered, the chance of that run going live may not be possible. The wires need to be tied into the receptacle to carry on the circuit.
    – Jack
    Nov 5, 2016 at 3:32
  • The receptacles were completed months ago and I've used them all. They just didn't have their faceplates because I was waiting for the walls to be finished. If it's back there, it's live.
    – bubbleking
    Nov 5, 2016 at 3:33
  • I tried the straight edge and did not see any bulge. The ony thing that worries me is that the duplex plugs were not screwed into the box, so if the wires were extended, it could have been pushed to the side of the stud, leaving only a few wires between the stud and the drywall, which might not cause a bump. I'm satisfied, though. It seems highly unlikely, given the results and some other factors, that there's an outlet back there.
    – bubbleking
    Nov 8, 2016 at 7:23

Good advice from @Jack about the hump in the drywall. If that doesn't work...

If the outlets are live, you might have luck with a non-contact voltage detector. For example, this one: https://www.amazon.com/Fluke-1AC-A1-II-VoltAlert-Non-Contact-Voltage/dp/B000EJ332O enter image description here

(There are cheaper ones out there... I wouldn't go to the bottom of the price barrel.) If you're doing anything handy in the future, these are super-useful.

Otherwise, you could kill the circuit and use a tone generator with a probe. For example, Fluke Networks makes the Pro3000. Bad news is those are pricey and really only detect wires.

  • I actually have one of these (a different brand) but hadn't tried it yet because I assumed it wouldn't differentiate between the wiring and the box. I'll give this a shot too.
    – bubbleking
    Nov 5, 2016 at 15:10
  • If nothing else, it might give you an accurate fix on the height above the floor. (Assuming your wiring is running horizontally...) Nov 5, 2016 at 15:57
  • Wouldn't it stand to reason, if the wiring is there, the outlet might be too?
    – tahwos
    Nov 6, 2016 at 0:59
  • I tried this, and was able to verify where wiring is (which I already knew) but nothing jumped out to suggest that there was a box and not just wiring.
    – bubbleking
    Nov 8, 2016 at 7:19

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