: a box (as of metal) for enclosing the junction of electric wires and cables.

What is a junction box and what is it used for?

Electrical boxes, also known as junction boxes, enclose wire connections. They help protect against short circuits, which can cause fires. This guide describes the different types of electrical boxes, their materials and their applications.

When would you use a junction box?

You'll need a junction box if you can't make the connections inside an existing electrical box. You should install the box with the opening facing out from the wall so all the wires inside are accessible. Like any electrical box, it should be installed so that the edge of the opening is flush with the wall.