What Is a Motion Sensor Light Switch? Key Benefits and Uses

Keep the lights on when you need them and off when you don’t

A floodlight on the exterior of a house at dusk
Photo: adamkaz / E+ / Getty Images
A floodlight on the exterior of a house at dusk
Photo: adamkaz / E+ / Getty Images
Highlights
  • Motion sensor lights offer convenience, security, and energy savings for your home.

  • Sensors can use sound waves or detect body heat to activate the switch.

  • Occupancy switches turn the light on when motion is detected, while vacancy switches turn the light off when there’s no more movement detected.

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Whether it’s lighting your way through the dark or discouraging intruders from sneaking around your property, a motion sensor light switch can come in handy. On top of the convenience and added security, motion sensor lights offer enhanced energy efficiency and cost savings that make them well worth the initial investment. If you’re considering adding this type of security light to your home, here’s a breakdown of their benefits and how they work. 

How Does a Motion Sensor Light Switch Work?

Motion sensor lights feature a special type of electrical switch with built-in sensors that automatically turn on the light when they detect motion. This device uses one of two types of sensors—active or passive. Active sensors emit sound waves and detect changes in the waves to trigger the switch, while passive sensors detect body heat to activate the switch.

Key Benefits of Installing a Motion Sensor Light Switch

A professional installing a motion sensor
Photo: AndreyPopov / iStock / Getty Images Plus / Getty Images

Installing a motion sensor light switch provides convenience, security, and more. Here are the top benefits of adding one to your property.

Convenience

Motion sensor lights conveniently provide a quick, bright light without the need to flip a switch. This type of outdoor lighting can help you navigate to your front door in the dark, illuminate the laundry room while your hands are full, and add a touchless light wherever you might have trouble finding the switch. 

Enhanced Security

It’s no secret that individuals with nefarious intent prefer slinking around in the dark—with a motion sensor light, you’re removing the chance for them to do it around your home. Automatic lights can also make it seem like someone is turning the light on and coming out to investigate, adding another layer of doubt and anxiety for potential criminals. Plus, with an automatic light, you’ll be immediately alerted of any changes to the perimeter of your property.

Energy Efficiency

A motion sensor light switch can improve your home’s energy efficiency if you regularly leave lights on where they’re not needed. A motion sensor light switch can also be especially helpful in places where you frequently forget to shut lights off, such as closets, basements, and laundry rooms. 

Cost Savings

If you’re replacing an always-on light or a light you frequently forget to turn off, the cost of installing a light switch with a motion sensor can be an excellent investment. Since it helps reduce your home’s energy consumption, it can help lower your energy bills, too. Plus, since they’re only on for a short time as needed, your light bulbs will likely last longer. 

Occupancy vs. Vacancy Light Switches

A mother reading a book to her daughter in the playroom
Photo: evgenyatamanenko / iStock / Getty Images Plus / Getty Images

When shopping for a motion sensor light switch, the two main types are occupancy light and vacancy light switches. Occupancy switches turn the light on automatically whenever they detect motion, and remain on as long as there’s still motion in the area. Then, after a preset time delay following the last detected motion, they automatically shut off. 

Vacancy switches, on the other hand, require manual activation to turn on the lights. Once they’re turned on, the lights will turn off automatically after a preset delay period once they stop detecting motion in the area. These are a great fit for a playroom, basement, or other room where the lights are often left on by accident. 

Hire a Pro to Install a Motion Sensor Light Switch 

Ready to add a motion sensor light switch to your home? It’s best to hire a professional electrician to install motion sensor lights to protect yourself and your home from the hazards of working with electrical wiring. Plus, a professional electrician can consult with you to determine the right placement for the motion sensor lights.

While it’s possible to install these yourself if you have the proper skills, it’s best to hire a local electrician to ensure the light switch is wired safely and correctly. Keep in mind that motion sensor lights cost $350 to $500, or an average of $425 for a first-time installation.

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