How to Troubleshoot an Electrical Wall Switch

Electrical wall switch pressed on top and bottom

The Spruce / Kevin Norris

Project Overview
  • Working Time: 5 mins
  • Total Time: 5 mins
  • Skill Level: Beginner

Most homes have a few different types of switches controlling light fixtures or electrical outlets. There are single pole switches controlling things from a single location, three-way switches controlling lights or outlets from two locations, and for larger homes or complicated situations, a four-way switch may be used to control lighting or outlets from three or more locations.

When a switch stops “switching” then it’s time to troubleshoot to learn whether the problem is the light, device, or appliance plugged into the outlet or attached to that switch. We'll guide you through the easy steps to determine where the problem lies.

Before you do any work on a switch, make sure power is turned off at the electrical panel. You may also want to use a circuit tracer to identify the circuit breaker or fuse you need to turn off.

Tip

If you have a device or appliance plugged into an outlet and you're not sure if the problem is with the outlet or the device, simply plug a lamp into that outlet. If the light works, the problem is the device, not the outlet.

What You'll Need

Materials

  • New light bulb

Instructions

  1. Check For a Flipped Circuit Breaker or Blown Fuse

    If you turn on a switch and hear a popping sound, that might mean the circuit breaker tripped or a fuse blew. Head to the electrical service panel and locate the breaker or fuse. Flip the breaker back to the ON position, or replace the blown fuse.

    Tip

    If the issue persists, it could be anything from a loose wire to a short circuit. A short circuit is caused when the hot wire (black wire) touches another hot wire or touches a white neutral wire. A break in a wire in the circuit can also cause this problem. Learn how to fix light switch breaker overloads.

  2. Replace the Light Bulb

    If the circuit breaker or fuse is just fine, it's likely the light bulb itself. If the light is flickering, simply tighten the bulb. If that doesn't work, the problem might be the setting on the lamp or fixture. Learn how to fix a flickering light bulb.

    If the light doesn't come on at all, replace the lightbulb with one of appropriate wattage.

  3. Feel for Heat and Listen for Buzzing

    Does your switch or outlet feel warm or even hot to the touch? Is there a low-level hum or buzz when you turn the light switch on? This might be a usual occurrence for some types of fluorescent lights, but not for fixtures that use typical light bulbs. Heat or a buzzing sound indicates a serious problem with wiring that needs immediate attention.

    Turn off the light switch, flip the breaker to the OFF position or remove the fuse for the switch, and call an electrician.

Exposed blue electrical switch box with short circuit wires

The Spruce / Kevin Norris

4:04

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