I went to put a retrofit LED light in my can light. But after completing it the light does not work. I even put it all back the way it was and still nothing. Double checked the bulb and it works fine. When testing to see if I had power I touch the tester to the black line going into to bulb screw socket and when I touch the other probe to the metal can housing itself I get a power reading. I get nothing when touching the black wire and white wire. Seems something is wrong to me and that the metal housing should not be hot or am I wrong?