These work simply by moving them around near the terminals of your switch. Wave the voltage tester all around the front and sides of the switch without making direct contact.

A Guiding Light To Dimmer Switches Flip The Switch
How to check voltage on a light switch. Use a non contact voltage tester to make sure youve shut the power off to your switch. Know how now 65029 views. You should shut the power off before you remove the cover plate on the light switch. How to use a multimeter for beginners how to measure voltage resistance continuity and amps duration. If the switch is good then there will be a reading or indication otherwise no reading or indication means that the switch is bad. Shut off the power.
Toggle the switch into the on and off position with the test leads attached to the terminals of the switch. With the power off remove the two screws that hold the cover plate on. According to the university of washington you should see a reading of less than 25 ohms. Turn the switch on. Touch the probes to the copper terminals on the side of the switch. Using a voltage detector see picture below place it next to the terminals on the switch.
Disconnect and remove the switch. See if there is voltage at one of the switch terminals. After that loosen the screws that hold the switch into the electrical box. If the tester detects voltage turn the switch on and see if voltage is detected at the other switch terminal. Identify the switch type. Shut off the circuit breaker that feeds the lighting fixture.
Test a light switch with a multimeter duration. Testing a switch with a voltage tester. Whenever you work with electricity caution is important. Shut off the power to the light switch circuit by switching off the appropriate breaker in your homes service panel breaker. Set up the voltmeter to read at least 240. You will need to take them completely out of the box to free up the switch.
How to test a light fixture with a voltmeter. Turn on the circuit breaker and the switch that feeds the fixture. With power on remove the cover from the switch and turn the switch off. This indicates that electrical continuity exists through the switch. Switch the multimeter dial so it points to v or volts if your multimeter has several voltage options choose 220v these numbers indicate the highest voltage the multimeter will read and 220 volts is the voltage of most household light sockets. Remove any covers and remove the lighting element.