In some types of light fixtures such as chandeliers, the hot and neutral wires are of the same color. In this case, the hot wire is usually smooth and the neutral wire has ridges on it (you can feel these ridges with your fingers). Before attempting light fixture installation or replacement, make sure the circuit breaker controlling that light is turned off and then check for power by using a non-contact voltage tester. After connecting the light fixture wires to the circuit wires in the ceiling/wall box using twist-on wire nuts, you can do the following simple test using a non-contact voltage tester to find out whether your light fixture is installed correctly: With the circuit breaker still turned off and no light bulbs installed yet, turn on the circuit breaker and then the light switch. If the wires are connected correctly, then the voltage tester will only beep when you place it closer to the center pin or tab inside the light bulb socket, meaning that the center pin is hot but the threaded shell of the socket is neutral. If the wires are reversed, then the voltage tester will beep when you touch the threaded shell of the light bulb socket, indicating that the entire socket is energized (potential shock hazard when installing or replacing light bulbs).
