I recently shielded my Squier Mustang this week with conductive copper tape. I put it in the pup cavity, control cavity, pick guard, and on top of the control plate. I soldered a wire from the control cavity to the pup cavity, measured with a multimeter and they were in sync with one another. I noticed the bridge ground wire wasn't soldered to the post, so I put a small piece of copper tape on the post and soldered the bridge ground wire. I wasn't sure if that was necessary or would cause problems, but if anyone has input on that I'd appreciate it. I went and plugged it in and it sounded great! No large hums or anything, but today when I plugged in to play I'm getting this crazy buzz.
The thing is that the buzz only comes when a single pickup is on, or when both pickups are out of phase with each other. When I stand close to my computer or close to the amp, it buzzes, but there is a sweet spot where its dead silent. The sound is some sort of electro wave (not sure if this is the correct term), sounds like a blaster just buzzing. I'm not sure if I've made a mistake with my shielding, but when I read the multimeter it looked okay. What I'm now wondering is should I solder wires from the bottom of the cavities to the top of the pick guard and the control plate? I made sure to overlap the tape in the cavities when I did the job so they'd touch.
The thing is that even before I shielded the guitar, when the pups were out of phase I got this crazy buzz sound too, is this common for these models? This is my first mustang btw. I'd provide pictures but I don't want to take the guitar apart unless I absolutely have to. Any tips are appreciated, thanks!