Let There Be Light!

August 22, 2007 5:18 PM

I need to locate two light fixture mountings that have been plastered over in the ceiling of my condo.

I moved in to a new condo with my girlfriend in May. In the living room and the master bedroom there are no light fixtures in the ceiling. There are, however, two non-functional light switches, one in each room. This makes me suspect that there were light fixtures once upon a time but at some point in the condo's past they were plastered over for some unknown reason.

Is there a way to locate where these fixtures are in the ceiling so that we can install some new lights? I'm thinking specifically of some sort of measuring device that can track electrical cabling inside a wall and using it to find out where it terminates.

Aside from locating these possibly non-existant fixtures, what are my options for installing new lights that hook up to the existing switches?

posted by talkingmuffin to Home & Garden (10 answers total)

Have you checked whether the switches turn a power outlet on and off instead?
posted by Gable Oak at 5:45 PM on August 22, 2007

Seconding Gable Oak - Check your outlets (top and bottom, as receptacles can be split). I think it's more likely that the switches control outlets than hidden boxes.

If you do have hidden boxes, most areas would consider that a code violation (for what it's worth).
posted by davey_darling at 5:55 PM on August 22, 2007

Living rooms and master bedrooms are often not furnished with ceiling fixtures. As Gable Oak said, plug some lamps into the various sockets in the room. Be sure to try EVERY individual plug, not just one in each pair.

Plus, in all areas that I'm familiar with, building / electrical codes forbid plastering over or otherwise making electrical boxes inaccessible in a ceiling or wall. On the off chance that someone DID seal up fixtures, they're generally going to be in the center of the ceiling.
posted by jjb at 5:59 PM on August 22, 2007

Hmm, on preview, I did not answer the original question as accurately as I could have.

A device such as this one is designed to locate live wires within walls. With your switches turned on, you should be able to locate wires/electrical boxes if they do in fact happen to be there.
posted by davey_darling at 6:03 PM on August 22, 2007

It's also possible that they used to be sconces instead of ceiling fixtures if the building is very old. These sometimes got plastered over (even though that is not cool code-wise). We have friends who have unearthed some of these.
posted by jeanmari at 6:07 PM on August 22, 2007

While I agree with previous posters, if you want to find stuff in your walls, get a rare-earth magnet from a science supply store. They are super strong and will find any hidden boxes underneath plaster in your ceiling or walls. Just get the magnet and slowly sweep it over the entire surface you're searching. You'll find the nails, screws and anything metal basically.
posted by GuyZero at 8:33 PM on August 22, 2007

A magnet will only find ferrous metal and therefor won't find electrical boxes if they are plastic.

However an electronic stud finder works by sensing the capacitance change of different materials in the wall and will find even plastic boxes. Cheap ones work ok and are around $15. It'll be tedious to sweep the whole ceiling but the box should be located either in the exact centre of the room or within one stud spacing of the centre.

That said I'd bet the switches control wall outlets as indicated by jjb and Gable Oak. It would be unusual for two rooms to have the ceiling boxes hidden.
posted by Mitheral at 10:57 PM on August 22, 2007

I must admit to being slightly vague as to what exactly a condo is, but can you get into the roof space? You should be able to see anything obvious from there. If not, is it possibly that your condo is the same or very similar to your neighbours'? If so, they might still have the original lighting, or know what the switches do.
posted by kjs4 at 11:38 PM on August 22, 2007

I'm going with switches to outlets as well on this one. Try that before trying anything else.
posted by davejay at 11:54 PM on August 22, 2007

Can you get into the crawl space? If so, and you locate the former boxes (if indeed there are any), just drill a small home down through the ceiling, maybe dangle something through it so you'll know precisely where you drilled, and voila, you'll know where to cut through the plaster.
posted by tr33hggr at 5:52 AM on August 23, 2007