RR3 shielding/high pitch feedback question

[rc2904]

When I wired up my old mutt I reversed the connections to the jack and it was pretty bad. I honestly sounds like a bad ground if it's with other pickups from another guitar that was good.

Yeah, I can see how thousands of ohms on the ground signal would create a bad ground. I just dont know if that would cause it to imitate a microphonic pickup or not. I would hate to spend all the time sanding and reshielding the cavities for nothing.