3-Way Switch

One light, controlled from two switches — a hallway or a set of stairs. Terminals: COMMON, TRAVELER 1, TRAVELER 2 on each switch; HOT and NEUTRAL on the source and fixture.

Build It

Start from unconnected terminals and wire a working 3-way circuit yourself.

Troubleshoot It

Pick from 3 pre-wired circuits, each with a real symptom, and find the miswire.