Old Box Wiring

BX wiring relies on its outer coverings to maintain a ground path. Each time a BX wiring circuit enters or exits a box, it uses a special connector with a locknut. This nut and connector must be tight, or the circuit will lose its ground path.

For example, if a circuit goes through ten different boxes (including outlets and light fixtures) before finishing, loose connectors at any point will degrade the ground connection progressively. This issue is commonly observed when measuring voltages, highlighting the importance of ensuring all connections are secure.