Installing a fan prewire for a home owner one day which includes cutting the box in the ceiling,An running the wire down the wall to the switch ,I opened up the box that was there for a half switch and it was a back feed, The home owner said the switch dose not work , Now i have no neutral for the fan, I found the half switch, which there were two. I figure out which would be the best locations for a half switch so i made that one the switched one and used the neutral from the outher receptacle.P,S come to find out the home owner had replaced the receptacles in the bedrooms . will be back!