I recently bought a Squier Vm mustang and it plays great when the two pickups are On and in the same direction, but if only one pickup is on or if the two are out of phase, there is some buzzing. When I listen closely it seems the buzz is still there when the two pickups are on but its very quiet. It just gets louder when I only one pickup is on, and even louder if both are out of phase! Should I shield my guitar? I know I'm probably going to change the bridge soon but the sound I hear is not the bridge it has something to do with the pickups.