I recently got a used Squire JV made in Japan.
The previous owner put EMG's in it and removed the ground strip that connects the bridge with the bridge pickup.
The thing hummed like crazy with singlecoils!
What to do? I wanted to fix the bass right away, but it was evening and no stores were open. I had no idea where to get a new brass strip here in Sweden anyway, so I started going thru my stuff at home. After a few tryouts i found a jew's harp laying in a drawer. This is how it turned out.
It's not copper, but i think it looks better with the steel showning.