lately i've gotten a little braver and have shielded the control cavities on a couple of my basses. then, i've also run an extra wire into the control cavity from the bridge. the extra wire i solder to the control cavity shielding and join it under the bridge with the existing ground. i then put a piece of shielding foil across the the two ground wires under the bridge. this seems to help quieten the basses nicely. anyone found a better way to do this or is this way "grounded" in theory... sorry for the pun.

If I'm understanding correctly you are running two wires from the control cavity (both connected to ground in the cavity) to the bridge, running a piece of foil between the wires. This is actually creating what is called a ground loop which will make things noisier as it will act like an antenna to pick up EM noise.

I'm not sure that I really understand what you've done though, the other thought I have about what you've done is put the cavity shielding in and then a wire is run from this shielding to the bridge and then another wire goes from the bridge to the ground on the output jack. If this is the only wire that connects the shielding then there would be no ground loop but I don't undestand why you wouldn't just run a wire from the ground lug of the output jack (or another lug inside the cavity if you are doing a star ground). It would be more direct and would eliminate the difficulty in having to run a second wire to the bridge when you could just go directly to the ground on the output jack.

Can you clarify which of these you've done? If it is the second case then you are seeing reduced noise because the cavity shielding does nothing if it is not grounded.

sorry, yes to clarify, i've done what you noted in the second part of your message. i see what you are saying about just running a shorter lead rather than running it up to the bridge. guess the only reason i've done this is because since i have the bridge off when i'm doing this (to ensure the ground is properly placed) i also put some shielding across the ground wire to ensure a good ground. hope that makes sense. and thanks for your message.