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.)