[Ken Smith]

It needs to be re-shielded with Conductive Paint. In time the paint can sink into the wood. Just the slightest break in coverage or lack of conductivity can cause the shielding to fail. This has nothing to do with the circuit or pickups failing. It is just the painted Shielding that protects it from that frying pan noise when the strings are not grounded by touch. Under lights or facing an amp can make it more noticeable as well as when boosting the treble control.