Test for continuity by using a multitester, sometimes referred to as a multimeter. The ohm setting on a multitester tests continuity, and it determines whether the connection through the device is complete or if it is no longer usable.
The symbol for ohm is Ω, the Greek letter omega. Choose the X1 ohm setting if there is more than one ohm setting on the tester. You can use an analog or a digital meter; the only difference between the two is that a digital meter provides a numeric reading, while an analog meter provides a reading using a needle. Perform the test when there is no current present. Unplug all devices that you are testing, or turn off the main circuit breaker. Test equipment for proper operation before use.
Each probe on the multitester should touch one of the terminals of each device. If the reading on the multitester sets to zero, the device has continuity. If you need to test a switch, place a probe on each pole of the switch, and then move the switch from the off position to the on position. The meter reading should change from infinity to zero if the switch is working properly.