Why are my LED lights glowing?
You have something else in the circuit that uses a small amount of power and which bypasses the switch.

A smart-switch of some sort will do this but there are other devices that also do this, for example a switch illuminator (so you can find it in the dark)




The issue here is that, at switch locations you generally do not have neutral present. Just live and switched live (and earth). So the illuminator cannot be wired in parallel but mus be in series with the lighting circuit. When you turn the switch on, it turns the illuminator off because the switch shorts the illuminator so that there is no longer a potential difference across it.

These things pass a very small current, at lower voltage, through the rest of the circuit. This is insufficient to make incandescent or halogen bulbs glow, but is enough for some LED driver circuits to start to work.