We were having a house built and the builders have gone bankrupt so we have been left to finish everything off ourselves. The plasterboard walls have been put in and the wires are behind the walls for the electrical sockets etc but they haven't been pulled through externally. Can anyone tell me how we locate these wires? We know that we can use a stud finder to locate the beams etc but not sure how to find the switch plates for the plugs etc. Someone suggested we use a magnet and pass it along the wall and we've tried this with a very strong magnet but it didn't work. We really don't want to start knocking holes in the plasterboard unless we're sure that the switch plates will be behind it and we have about 70 to locate. Any help would be appreciated - thank you.

  • 3
    In a normal situation, the drywall installers would have cut the openings as they installed the drywall. Very strange for them to have put up all the plasterboard without cutting any of the openings. Typically the junction boxes protrude the thickness of the plasterboard so it wouldn't be possible to get a flat wall without cutting the openings.
    – BMitch
    Dec 28, 2013 at 12:14
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    I'm hoping that these wires terminate in standard electrical boxes, correct? Dec 28, 2013 at 20:29

1 Answer 1


I'd use a toner-tracer designed for locating telecommunications wires. Remove each breaker, hook up to the bare wires, and use the tracer to find the first segment. Pull it, and lather rinse repeat to the end of each run.

These are also called "fox and hound" units.

  • This is also called a "tone probe". Dec 28, 2013 at 13:47

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