How to Install an Automatic Light Switch

pushing a light switch on a wallpapered wall.
  • 1-3 hours
  • Intermediate
  • 0-50
What You'll Need
Automatic light switch
Wire cutter
Electrical tape
Wire nuts
Circuit tester

Automatic light switches turn on and turn off lights, both indoor and outdoor, automatically. There are two main types of automatic light switches. The first are programmable switches that turn on at a specific time and remain on for a specified time before automatically turning back off. This type of switch allows you to turn the lights on before you get out of bed, or automatically turn on and off while you’re on vacation. The timer is typically located on the switch for easy adjustment, or in an app that controls your smart home settings.

Another type of automatic light switch works with the help of a light sensor. This switch turns on and off depending on the amount of light reaching the light sensor. As natural light fades, the automatic switch turns the lights on for you. These switches can save you money by using less energy when lights don't need to be on. These switches also provide safety by automatically lighting up dark rooms.

Because of the whiz bang factor of these devices, you might think installing them is a difficult task, but it can be done with just basic knowledge about electrical circuits.

Step 1 - Turn off the Power Supply

First you must turn off the circuit breaker and make sure there is no current in the circuit where you are wanting to install the switch. You can test it with a basic circuit tester. You can also switch off the power supply from the mains as an added precaution.

Safety Note: Always turn off the power to a circuit you're working on, or you risk dangerous electrical shock.

Step 2 - Remove the Old Switch and Wiring

hands removing old light switch

Use the screwdriver to loosen and remove the screws from the existing switch plate and switch box behind it. Then pull out the switch with the attached wires. Next loosen the screw of the terminals where the live wire, neutral wire, and the ground wire are housed. These may also be attached with a clip instead of a screw.

After disconnecting these wires from the switch, check whether the wires are in a proper condition. If the end of the wire is damaged, cut that portion and use the stripper to remove about half an inch of the insulation to expose more wire.

At this point, you may want to label each wire for easy reference. Another option is to take a picture before disconnecting the wires so you can remember where each wire was attached. Alternately, you can disconnect one wire at a time and move each to the new switch in order.

Step 3 - Connect the Automatic Light Switch

Like any ordinary switch, the automatic switch has two terminals at its back side and one ground terminal. Connect the two wires with the two terminals of the switch and the ground wire with the ground terminal.

Often the ground terminal is on the side. Tighten any screws properly and ensure no extra wire is coming out from the terminal that might cause sparks and damage the switch. In some cases you might require wire nuts to fix the connection. In most automatic switches it is not needed but if required use them.

hand installing new light switch

Step 4 - Install

In most cases the size of an automatic light switch matches an ordinary electrical switch. So the switch goes in and fits perfectly in the switch box and you do not need to change the space where the old switch was present. In case it’s bigger, such as if you are adding a double switch, you can replace the switch box.

To do this, cut and widen the slot for making a bigger space. Use a drywall saw to carve out a bigger hole. Then mount the new, larger switch box to a stud. After putting the switch in place tighten the screws to hold the automatic switch in place. Replace the front plate.

Step 5 - Turn on the Power

Turn on the power supply and your automatic light switch is ready for use.