For years we’ve had a motion-sensing light switch in our laundry room. This controlled power to a conventional 4’ fluorescent tube light on the ceiling. Since we pass through this room every time we walk to/from the garage, this lamp gets a lot of on/off cycles, so the tubes have had to be replaced frequently.
Having finally used up a box of replacement tubes and not wanting to buy more, this weekend I replaced the fluorescent array with an LED light. I have previously installed several copies of this same LED light in my garage, wired to a conventional mechanical light switch, and they work great. However, when powered by the motion-sensing switch in my laundry room, this light buzzes with annoying volume. The interesting thing is that this particular motion-sensing switch also includes a slider that you can move to force the light to stay on - and when you move this slider to the permanent-on position, the buzzing stops.
OK, so my guess is that that slider is an actual mechanical switch, and the motion-sensing switch is some sort of solid-state device (there’s no audible “click” when the motion-sensor turns the light on, unlike some other motion-sensing switches I’ve seen).
So why does the LED light buzz when power is being delivered through the motion-sensing switch?
TLDR: You need a LED-compatible motion sensor switch. Or you can get cheap LED bulbs (not tubes, just normal screw in ones) with built-in motion sensors that face downwards from the ceiling.
Like reply said, you need to get a switch meant for a LED light. If the switch doesn’t have a neutral, a bit of of rewiring may be needed as well, but I’m guessing it does. Another issue you can run into is that the lights will always be on very dimmly, but again, if there’s a neutral in the switch box, you should be okay.
If that switch controls a regular light socket, try plugging a regular incandescent bulb into it. The extra load may make the LEDs stop buzzing. Not an ideal solution, but a good way to verify that it’s the switch and make it stop until you get a new one.
Yeah, we have the issue with the lights staying slightly on when we put LEDs in our kitchen recessed lights. It’s no biggie. It’s like have an unintentional night light if I come downstairs in the middle of the night. And loads cheaper than doing any rewiring (we’d have to hire an electrician.
