Always turn off the power before working on a junction box. You don't want to be the unlucky person who comes across a highly dangerous hot wire.
Finally, punch out a hole to provide a path for the wires to enter the box. Use a cable clamp to secure the Romex wiring that comes into the box, and cap wires inside the box with wire nuts. If you have difficulty twisting the wires together, use pliers to wrap black to black and white to white, before attaching the wire nut. Then, ground the box securely.
Installing the Box
Professionals usually recommend installing a junction box by bringing a new wire from the main electrical panel to the box rather than tapping off an existing electrical box. You do this to avoid circuit overload, which helps protect against a potential electrical fire.
When adding a circuit to an older home, run a new Romex wire from the electrical panel. You do not want to plug an expensive big screen TV or a computer with essential data into an older, two-wire receptacle.
You can buy junction boxes at most hardware or home improvement stores. A junction box usually costs less than a dinner for two at McDonald's and increases the safety of your home's electrical system. While at the store buying your box, pick up a couple of extra covers for any uncovered junction boxes you might find in your home's garage or during an attic inspection.
Electricians typically secure a junction box to a strong structural location, such as a stud or joist, which is essential if the box supports a light fixture. Some junction boxes have wings that fit within a cut-out drywall hole, but most of these boxes are not sufficiently sturdy or stable for supporting heavier light fixtures. Be sure to check the listed weight capacity of the box used and the weight of the fixture you are installing, and never use a winged box for a ceiling fan installation.
People sometimes call a receptacle box a junction box and use the words interchangeably. But, keep in mind that this term is sometimes used more generically and is not always referring specifically to a junction box. Other types of electrical boxes that serve different roles include:
· Mounting box
· Fixture box
· Handy box
· Remodeling box
· Light switch box
· Receptacle box
· Outlet box
· Electrical box
· Ceiling fan box
