I have recently replaced a ceiling fan with light kit with a newer model. I hooked up the wires from the new fan/light to the same wires in the ceiling box that the old fan was hooked up to. There are two switches on the wall plate, one for the light and one for the fan. When I hooked up the new fan/light, everything seemed to be working, but the fan motor made a humming noise that wavered in pitch slightly. This fan worked for about 2 weeks, making the noise, but then we smelled a faint electrical fire smell coming from the fan. I replaced that fan with one just like it, thinking that the motor was defective. After I installed the second fan, it too made the same humming sound. We ran that fan for about a week, and then the fan suddenly stopped working. Alas, I took that fan back, thinking it was another defective fan. I bought a third fan/light (different brand) and it too makes the same humming sound. Sounds like I might have a wiring problem, but I don’t have any shorts or arcing. Any thoughts as to what might be the problem? It has been suggested to me that the problem might be in the wall switch itself. Something about low voltage!