Learn how to wire a 3-way light switch with clear diagrams and step-by-step instructions. A 3-way switch lets you control a light from two locations and is commonly used in hallways, stairways, and large rooms.. A 3-way light switch enables a light to be controlled from two different locations. Learn how to install 3-way light switches in this easy step-by-step guide.
One wire comes in from the power source, and one wire goes out to the light (s). A 3-way switch adds two terminals for travelers, which connect two 3-way switches together.. A 3-way light switch allows you to control a light source from two separate points. Although a 3 way is one of the hardest electrical circuits to figure out, it's also one of the most useful. Note: there are several ways to install a 3 Way.