We bought this house a few months ago, and there is a very interesting problem with the ceiling light in the back room. The ceiling light is turned on or off using one of two switches. One switch is in the kitchen along the door frame, and the other is in the back room on the wall beside the door. The problem that I am having is that the light is caught up in some strange state where one switch only dims it, or barely turns it on, while the other works correctly in an on off fashion as one would expect. If I flip both switches off then go back to the one that was working, it starts to behave like the other one, and only brings it up to a dim state when trying to flip it on. In other words, either switch can be bugged, depending upon the orientation of its partner switch. Which ever switch is currently "the odd switch out", appears to act as a dimmer, and it's a dimmer that cannot go to full brightness.

When either switch is in "the bugged state", both switches produce a low "humming" sound.

I'm pretty sure that something is off about the wiring. My question is, what is this called? I've tried Googling, but I'm not sure what the correct terminology should be that would help me find a video, or solution. Also, if someone is experienced in this specific problem, can you explain why it's happening, and how I could go about fixing it?

Expected Behavior: Light switch A or B turning on or off the ceiling light, regardless of the switches on or off state; for either switch to not dim the light at all.


  • does the order of operating the switches change the result?
    – Jasen
    May 20, 2020 at 2:27
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    Turn off power to the circuit, remove both switches from the wall but do not disconnect any wires and take pictures of all the wires/switches and upload them here. I'll bet you've got at least one loose or pinched wire. May 20, 2020 at 2:36
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    @manassehkatz-Moving2Codidact I will post pictures tomorrow. It should be noted that when either switch is "in the bugged state", both of them hum. I"m to understand that this means something is arcing? Idk. I'll do the pictures tomorrow and message you when I do so.
    – Krythic
    May 20, 2020 at 5:13
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    Does one of the switches happen to be a lighted switch? May 20, 2020 at 5:36
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    Two switches taken together can be in one of exactly four states: up-up, up-down, down-up, and down-down. For each of the four states, please describe the condition of the light, i.e., off, on, or dim. Don't be afraid to sound overly precise or pedantic in your descriptions. May 20, 2020 at 6:03

1 Answer 1


It sounds like you have an old school 3 way dimmer switch, the dimmer only works when that switch is in the loop. Newer electronic switches don’t have this problem I like the lutron maestro these work together so the dimming works at both locations , they also have a 10 second fade to black that gives time to cross a room. They are expensive but will solve your problem , this or replace the 3way dimmer with a standard 3 way switch.

  • I"m skeptical of this explanation, especially since the OP claims that both switches are binary. May 20, 2020 at 15:02
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    There are dimmers that look like toggles when these get flakey the do act like what the op is experiencing.
    – Ed Beal
    May 20, 2020 at 16:13
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    Actually, a badly connected traveler accounts for most of what OP has reported so far. May 20, 2020 at 22:34
  • And your experience? It could be a backstab but the op said like a dimmer I will stick with my answer as I have seen them many times even been given them when a new switch fixed the problem and yup they were the toggles that were dimmers.
    – Ed Beal
    May 21, 2020 at 0:33

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