In my second floor master bedroom there is a light switch right when you enter the room. It does not appear to control anything. I have separately checked every wall outlet and they all work with the switch off. There is a ceiling fan with no light that works with the pull chain when the switch is off. There is not other overhead lighting

If I add a light kit to the fan, or install a new fan with a light, is there a chance that the wall switch could control the fan light? Maybe there used to be a fan with light that was replaced to only be a fan - could you wire a switched fan to work without the switch?

Behind the switch: a look into the box shows that the switch is connected with red/black wires both tested and live. These red/black wires go up. There are two other points wired with black and white using the same box. One set also going up and one set going to the right. It also appears that the power source comes into this box. From the top of the box, left to right...red/black to switch, black/white/yellow, black/white. Out the right side...black/white.

enter image description here

hard to see but this is the inside of the outlet that contains the red wire. This outlet is furthest from the switch in the opposite corner of the room. Red wire comes into the box, gets capped with another red wire and then exits.

All outlets in the room are checked and only one contains the red wire. It does not connect to the outlet though. It goes into the box, gets capped and then exits. I have not taken the fan down yet but that might be my next step. Thanks for the input so far.

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This is inside the fan cap where a light kit can be installed. Does this red wire coming through mean I found what has come from the switch or do I still need to get the fan off from the ceiling?

Here is the fan connection to the ceiling... enter image description here

***Both red and black wires coming from the ceiling are testing hot/live when the switch is in the on and off positions

  • 7
    Have you checked both halves of your wall outlets? This sounds like a classic split outlet switch circuit, like I have in my own bedroom. In my case only the bottom halves are switched.
    – isherwood
    Dec 7, 2020 at 20:37
  • Yes all sides of all outlets have been checked and all work with the switch turned off. Dec 7, 2020 at 20:48
  • 1
    Have you taken down the fan to see what wires are in the ceiling box?
    – Mark
    Dec 7, 2020 at 20:54
  • It looks like you have 2 accounts probably due to not registering the account. Once that's sorted, please post photos of the insides of the boxes. Don't disconnect anything, just push the devices to the side so we can see wires attached to them and also what's in the back of the box. Dec 7, 2020 at 21:12
  • 1
    Can you post photos of the insides of the boxes involved please? Dec 8, 2020 at 0:33

1 Answer 1


If both sides of the switch test as hot with the switch in either position, I'd give odds that the switch is supposed to control a half-switched outlet. What has probably happened is that someone replaced the outlet and didn't break the tab on the hot side. The result is that the always-hot side is also feeding the switched-hot side through the unbroken tab. enter image description here [Photo from another stackexchange post]

Check the outlet boxes, looking for a dual receptacle with both black and red wires going to the hot side but an unbroken tab. Breaking off the tab should fix the problem.

  • I checked all the outlets and the furthest away in the opposite corner has a red wire. It comes in, gets capped with another red wire and then leaves the box. Never actually connects to the outlet. This is the bottom pic in the edit to the post. The first two pictures are the actual switch box. The first one shows the red wire connected and leaving the top left of the box. The middle pic shows the right side of the switch box. Dec 10, 2020 at 2:28

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