Wire hot with light switch turned off

dangerouswithtools

Installing a ceiling fan in 40 year old house. I removed the old ceiling fixture - in addition to black hot and white neutral attached to fixture, there is a black wire attached to a white wire in the box. This light is controlled by only one switch. With the wall switch off, my tester light is very bright touching the hot wire and the metal box - and the test light comes on dim when I touch the hot and neutral with the tester light. The circuit includes two rooms, each with a switched ceiling light and 6 wall outlets. Is there something wrong here?

comp1911

Sounds to me like the hot feed comes into the light box first not the switch box.

dangerouswithtools

Would that also account for the dim tester light between the black and white with the switch off?

rjniles

It sounds like the power is feeding the fixture box and you have a switch leg run to the switch box. The white wire connected to the fixture is the supply neutral, the black wire (supply) from the same cable is connected to the white wire to the switch. The black wire from the switch is connected to the other side of the fixture. This is the proper way to run the circuit when the supply feeds the fixture box, but the white wire that is connected to the black supply should be black tapped at both ends (fixture and switch) to show that it is hot. Make sure the box is rated for a fan and is properly secuered. Nailed to the side of the joist is not good enough unless you secure the fan bracket directly to the joist and not to the box.