Chadnliz, don't know if this will help or not, but for instance:
DACT recommends that the lead of a 1MOhm resistor be placed beneath the locking nut of their attenuators if the attenuator is mounted into an insulated part without ground, especially if the unit has metal knobs.
One lead of the resistor goes beneath the attenuator nut and the chassis mount and the other lead goes to signal ground.
This procedure is to to avoid static electricity generating audible noises in the speakers when the attenuator is operated.
I suspect this simple fix might cure your problem.