I have a ceiling fan/light with wiring for controlling the light and the ceiling fan separately. I have two separate switches in the wall. I have installed two separate Lutron fan control switches with a slide to control the speed. Each time the switch works fine after being installed but begins to buzz or sound like it's shorting out internally in a few hours after being installed. This is with the fan switch off. The wall box has one black wire, that is hot, coming in and one black wire, that is not hot, going out to the fan. Am I just getting bad switches or is something else going on?

If your slide switch makes a buzz then return it. Be sure you are buying a switch made for a ceiling fan. Although they slide they are actually making 3 separate speeds.

If your slide switch makes a buzz then return it. Be sure you are buying a switch made for a ceiling fan. Althought they slide they are actually making 3 separate speeds.

The switch has an on/off toggle just like a normal light switch and in addition it has a slide. It buzzes with the switch "off", so no should be flowing through the switch. I've replaced it already once with the same results, that's why I'm curious if something else, such as a bad fan, could be causing this issue.

The buzz is an electrical short, if the switch does the buzz, in the OFF position, then the switch is faulty. If your fan shorted the breaker would pop but neither would happen if the switch is OFF. What model did you buy?

It's a Lutron switch made for ceiling fans, I don't have the model # handy. The first switch I put in would buzz in the off position and if I wiggled the toggle side to side the ceiling fan would move, which indicated that power was going through the switch with it turned off. I agree with your assessment that it is a bad switch but I installed two separate switches purchased from two different locations with the same result so it made me curious if something else might be going on. Thanks for the input.