The dimmer switch is probably part of the problem, but I'm prone to suspect bad grounds, etc. being responsible for some of the trouble. A high resistance or nonexistent ground path causes voltage to back up through places it's not intended to go and cause all sorts of sneaky gremlins to appear out of nowhere- - - -usually intermittently.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!