I have a 2015 American Standard Fender Jazz that is completely stock. Just noticed this week (has it happened in the past? I don't think so, but I could be wrong) that there seems to be a grounding issue. When I plug it in, there is a hum. The hum goes away when I do 1 of 3 things: touch the bridge, touch the screws on the neck pickup, or roll off the treble completely. The hum gets LOUDER when I touch the bridge pickup screws. It's not a string issue (tapewounds...but I get the same results with flats and rounds). I've read enough to know that it could possibly be fixed by shielding the electronics cavities. And it's not the amp. My other bass does not hum at all. Anyone got an easy fix?