A malfunctioning light switch may not seem like a big deal. However, it can be a sign of other electrical issues, such as a wiring problem. Underlying issues or a defective switch can contribute to additional electrical damage or a home fire. Here are some of the most common light switch problems and answers to frequently asked questions to help you realize when to call a professional electrician.

1. The Light Doesn’t Turn On Right Away

If there’s a delay between when you flip the switch and when the light turns on or off, parts inside the switch are wearing out. The electrical contacts may not be making the connections they’re supposed to. Even if the issue occurs sporadically, a loose connection or short circuit may be to blame.

2. Mechanical Problems

Light switch issues are often caused by a broken mechanism. If there are any mechanical issues, the switch will likely need to be replaced. Signs of mechanical failure include:

  • The Light Doesn’t Turn On: Regardless of how many times you flip the switch, the light won’t turn on. 
  • The Toggle Is Loose: If the toggle wiggles back and forth, excess movement can wear out, fray, or damage the wiring behind the switch.
  • The Switch Sticks: If the switch sticks, the mechanism may be worn out or outdated.

3. Flickering Lights

A light bulb may flicker at random or when you walk by. There can be various causes. The bulb may need to be tightened or there may be a loose wire connection. Many people pass off a flickering bulb as no big deal, but oftentimes the underlying reason is a significant electrical problem. There may be abnormal voltage fluctuations or inadequate wiring.

4. Tripped Circuit Breakers

It’s not always easy to tie a tripped breaker or fuse burnout to a problem with a single switch. The issue isn’t always with the breaker or fuse. The light switch might have gone bad. If there isn’t anything wrong with the electrical panel, a malfunctioning switch may need to be replaced. Other times, the fuse or breaker might just need to be changed. An electrician has the knowledge and tools to quickly find the source of the problem and make repairs.

5. Sparks

Electricity normally arcs between the contacts as they move apart, so you may see tiny sparks when you turn a light switch off. However, if the spark is large, makes a distinctly audible sound, or is accompanied by smoke, the problem must be addressed immediately. Call for help if there’s a big spark or any type of spark if you’ve never seen one before with the switch in question.

6. Noise

A buzzing, sizzling, or popping sound from a light switch can be due to a loose wire or switch problem. Dimmer switches may buzz because of the design of dimmable light bulbs. The dimming effect sometimes causes vibration in a bulb’s filament, so check the bulb first.

7. Heat

While a dimmer switch may feel warm as it dissipates heat, a typical toggle-type switch should always feel cool. A warm switch can mean: 

  • An Issue with Electrical Flow: Damaged wiring may be causing electricity to arc or leave the circuit, or something is causing an abnormal flow of current. 
  • The Switch Isn’t Rated for the Application: If the device isn’t designed to handle as much current as is present, it can be overloaded.

8. Burning Smell

If you turn on a light switch and it smells like it’s burning, the switch mechanism or a connected wire may have gone bad. A burning odor can also indicate a short circuit or other electrical issues. Turn off the power to the switch and contact a professional.

9. Cracked Switchplate

Wear and tear can lead to cracks forming on the switchplate, which can put stress on and damage the switch. In some cases, cracks can indicate a more serious mechanical or electrical problem. The quality of the material or installation can impact susceptibility to cracking.

Frequently Asked Questions

Is Replacing a Light Switch a DIY Project?

A professional should always handle light switch replacement. Doing it yourself risks shock and injury. Whether your local municipality requires a permit for such work or not, don’t take a chance. An electrician is familiar with best practices, building codes, and safety standards and will avoid costly mistakes.

What Are the Dangers of Wiring a Light Switch Incorrectly?

Aside from causing an electrical shock or fire, an incorrectly wired light switch may not work at all. The light may flicker, and an improper flow of current can damage the switch and the light fixture. There are also nuisance issues, such as if the switch is wired backwards. In this case, the light will turn on when the switch is in the “Off” position and off when it’s in the “On” position.

How Does an Electrician Check for a Wiring Problem?

A reputable electrician will check for potential wiring issues when replacing a light switch. They’ll look for frayed or damaged wiring and exposed wires that have lost their protective coating. Cracked insulation is a serious problem that can lead to an electrical fire. For less obvious issues, they may use a voltmeter or multimeter to measure a wire’s performance and determine if it should be replaced.

Is It Dangerous to Mix the Hot and Neutral Wires?

This is a concerning risk with DIY light switch repair. If you switch the hot and neutral wires in a circuit, the light fixture may seem to be off but have a live current running through it, which is a serious shock or fire risk.

What Does It Mean If Multiple Light Switches Aren’t Working?

If more than one light switch in your home isn’t working, there may be a wiring issue or another problem with your electrical system. It can be an immediate safety hazard. Call for help right away.

How Much Does Light Switch Replacement Cost?

Installing a light switch costs $150 on average. However, it may cost as little as $60 or as much as $300 depending on labor and the type of switch. A standard unit costs less than a double switch or a dimmer or timer switch. For parts alone, most switches cost less than $25 (smart switches and timers can cost $100 or more).¹

Contact Express Electrical Services

A premier electrical services company in Los Angeles, we’re familiar with all possible light switch issues. Our licensed, trained, and certified electricians provide professional light switch repair and replacement throughout Southern California. We’re available 24/7 for emergencies. However, our team is also experienced in lighting design and automation. For light switch help by a qualified electrician, call us at (855) 590-8785.


  1. https://www.angi.com/articles/how-much-does-it-cost-replace-light-switch.htm