I’m trying to cap a ceiling light fixture box since we have no need to put a fixture on it. The electrician put a porcelain light fixture on it as a temp solution. The ceiling box has two black and two white wires in it and the switch the light is on feeds 3 other lights used for a bookcase. How do I wire these to make sure the bookcase lights still work?
If this is in the middle of the run to the other lights being controlled by the switch (i.e. capping each wire individually means that some lights won't work, and there's no reason the electrician would have installed a temporary porcelain fixture if a simple capping would have done the trick) then:
- Turn off power at the breaker.
- Remove temporary porcelain fixture.
- Using a yellow or red wire nut* connect the two black wires.
- Using another wire nut, connect the two white wires.
- Double check both nuts are tight by holding the nut and trying to pull each wire out.
- Push the wires into the box.
- Attach a round, blank cover plate.
- Turn on power at the breaker.
*Check the package labeling to ensure you're using nuts of the correct size for the wiring you're using. My box of orange says it will not support two #12 or two #14 wires, only 1 of each with something #16 or smaller. My box of yellows says it will support two #14 or two #12, as does my box of reds.
Of course, it strikes me as very unusual that the electrician wouldn't have done this in the first place. Surely he would have had a blank cover plate on the truck just as readily as having a porcelain. OTOH, he may have made more profit by charging you for the "temporary" porcelain than he would have for just putting a cover plate on it in the first place. :/
you should use a voltage tester to find which wire/wires are the powered ones. If the black wire and the accompanying white wire coming from the switch are the powered wires; that is Black is Hot and White is neutral than twist them to the other wires (ie Black to Black and White to White). Use an appropriate wire nut depending on the wire gauge. Red or Yellow for 12-14 gauge wires. Use a ceiling globe (?) or something decorative to cover the box. Don't bury it must be accessible.