What causes a light switch to stop working but light stays on?

A light that stays on when the switch is off usually means the switch has failed in the “closed” position or the circuit is miswired. Other common causes include a miswired 3‑way switch, line and load tied together in the box, a stuck smart‑switch relay, or a short at the fixture bypassing the switch. Our licensed Denver‑area electricians troubleshoot and repair switch, wiring, and breaker issues, including rewiring if needed in Denver and Thornton.

Quick checks:

• Try the other 3‑way switch (if present).
• Turn off the breaker and call a pro. Do not work live.

Updated: 2025-11-03 00:00:00

Need help in Denver, CO? Call (303) 451-5057 or book online.