I was installing new LED lights in the garage when I noticed that the lights turn on (dimly) as soon as I connect just one cable. (doesn't seem to matter if L or N).

The light is definitely not connected to anything else. In fact, I had it hanging from the ceiling just on that one cable, not even touching anything else and it was on. It's dim, much less then when it's actually on, but clearly visible in daylight conditions.

Searching, I found this question which describes a similar phenomenon. However, I am not sure the answers fit my case as there are no neon signs or other active electrical circuits in or around the garage. In fact, the closest active electricity would be the fridge in the house, a distance of about 10m.

Also, how do I fix this? Should I connect the ground wire to the lamp? (I haven't done that, because the wire from the switch doesn't carry ground - the old lights are all incandescant and have only two wires going from them to the switches.)

1 Answer 1


It could be the same phenomenal that is referred to as a "zombie bulb" in this video.

As far as I understand it, long strips of wire in the wall act as a capacitor, which allows some power to flow to the LED. Apparent more expensive LEDs have components that prevent this.

  • Possible. There's about 3m of cabling between LED and switch, but there's a lot more wiring in the garage and from the garage into the house.
    – Tom
    May 30, 2021 at 12:26

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