A light switch is the simplest of electrical devices. Flip the switch, electricity flows. Flip it again, electricity stops. Lights on, lights off. That’s great for a small room with one entrance.

All products featured on Architectural Digest are independently selected by our editors. However, we may receive compensation from retailers and/or from purchases of products through these links.

Before you attempt to fix a faulty light switch, make sure you understand the basics of light switch wiring. Being a smart ...