Question for elec techs

RJsfishin wrote:
I installed a 120v led light outside on the garage, and decided to switch the white wire, instead of the black (hot) wire. All worked fine, except for when it got dark, the light burned about 1/4 brightness (good guess) w/ the switch off. The bare grnd is running in the romex, and connected to the plastic box, but is in no way connected to the porcelain fixture, except under 1 mounting screw.
Why is it burning ? I should have taken a photo, but didn't think of it.
All I do know it that I change to switching the black instead of the white, and now no lite is visable when dark. I have never seen this before. But one clue, mite be that this is a very low wattage bulb.

Any ideas ?

OK.. Not sure as to the reason you used the neutral as the place to insert the switch..

BUT it is a BAD idea in the first place and needs to be removed.

Switching the neutral presents a huge danger and should never be done, basically you have a HOT loop from the light back to the switching point.

The light is in the middle and your white neutral is hot until your switch is turned on. When the switch is turned on the neutral is now connected to the neutral of the breaker panel.

The reason you see the LED glow is from the fact that it takes very little current/voltage to make a LED glow (even just a little). The switched neutral wire coupled with the hot unswitched wire is presenting 120V AC to the LED at all times.

In AC voltages you can get what is known as "capacitive" coupling.. The switched neutral wire along with the light fixtures grounding can easily act like a capacitor and pass enough current to light the LED slightly.

"Knob and Tube" wiring was eventually abandoned partly due to the fact that the FUSE was placed on the NEUTRAL wire and not the HOT wire.. Created a danger when the fuse opened and left a very hot and live wire..

Please undo your switch and wire it correctly and your problem will be fixed.