42.3-Way Switch
What Is a 3-Way Switch and How Does It Work?
A 3-way switch lets you control one light from two different locations—ideal for staircases or rooms with multiple entry points. But what is a 3-way switch exactly? Unlike a standard single pole switch, it has an extra terminal and no ON/OFF markings. The added terminal connects to a “common” wire, enabling communication between the two switches. For example, you can turn a ceiling light on at the bottom of the stairs and off at the top. If you need even more control points, a 4-way switch is used in conjunction with two 3-way switches. Wondering how to replace a 3-way light switch? Simply cut the power, snap a photo for reference, and transfer wires one by one—it’s a straightforward home upgrade.
