I’ve seen this done. At times when shielding the cavity of the instrument, when the pickguard is replaced the shielding material can touch the eyelet’s on the pickup and short out. Also make sure the wires soldered to the lever switch are not hitting the inside wall of the shielded cavity. Make sure the lead wires from the jack are connected properly. If they get reversed, all the hardware and strings become hot and will make lot’s of noise to the touch. Make sure all the connections between layers of shielding tape are properly grounded. The adhesive on most tapes is non-conductive and can cause noise problems if not properly grounded.