Switch for a Ceiling Fan?

In the house I just bought there is a Ceiling Fan in the Kitchen. There is a nob controller on the wall. When the home inspection was done the guy said this was the wrong switch for the fan and that it would over heat, he said sometimes you could feel the screws on the switch and they would be hot. So if a nob controller (I ume this was a dimmer switch for lights) doesn't work, what kind of switch should I put in there?