I have a Hampton bay ceiling fan with only a remote control. Periodically the fan turns itself on or the lamp comes on by itself. ( I actually have two of the same fans in different rooms with one doing it more frequently than the other) I've tried to see if I can change the codes on the fan but have been unable to locate the switches in the fan. Any ideas?

That's what you will have to do. The switches can be on top of the fan, in the ceiling canopy, or in the switch housing near the light.

Ceiling fan remote controls - help and FAQ- Ceiling Fans N More (http://www.ceiling-fans-n-more.com/ceiling-fan-remote-controls.php)