Originally Posted by: JFRICKThat noise has happened to me a few times in the past....Just takes a squirt of cleaner in the pot. Worked for me. I don't know what the cleaner is called, the guitar tech at my local store did it......It's some kind of lubricant kind of like WD-40.

It's probably not a "lube"... it's probably some kind of a contact cleaner. Which will take away the rust or whatever it is that's causing the interference in the current.