So I switched my regular incandescent ceiling light bulbs to LED bulbs. 4 ceiling bulbs controlled by a dimmer switch. I know, I know, the dimmer function will not work on the LEDs, but I don't care as long as the light's on or off when I want. Now, this is the weird thing: with the dimmer tuned off (click), the first three bulbs stay off, however, after I screw in the last bulb, all four bulbs emit light, albeit at a low level, but well discernible. Does that mean there is a current leakage at the last fixture?

I'll put odds on your switch being in the neutral, but first try replacing the dimmer with a regular switch.

 

On 18/09/2017 at 1:43 PM, klauskunkel said:

So I switched my regular incandescent ceiling light bulbs to LED bulbs. 4 ceiling bulbs controlled by a dimmer switch. I know, I know, the dimmer function will not work on the LEDs, but I don't care as long as the light's on or off when I want. Now, this is the weird thing: with the dimmer tuned off (click), the first three bulbs stay off, however, after I screw in the last bulb, all four bulbs emit light, albeit at a low level, but well discernible. Does that mean there is a current leakage at the last fixture?

Some LED bulbs will work with your dimmer switch check the boxes.

 

some led power supplies will show the effect you have if there is any current flow. Incandescents will not light at the same flow.

On 9/18/2017 at 4:50 PM, Crossy said:

I'll put odds on your switch being in the neutral

Yea, the dimmer switch installed on the Neutral Wire can cause this effect with fluorescent and LED bulbs.

 

Also if a dimmer has any indicator lights, memory presets, or 'remote' functions, it can be designed to allow small amounts of current to flow through the circuit to support this ...and it might be just enough to trigger the LED lamp it's meant to be controlling.