Tube fluorescent light fixtures use a different type of socket to connect the tubular bulb. The bulb slips in and out of two sockets that resemble tombstones. Although it is rare, a tombstone socket can become faulty. When this happens, you will have to replace the tombstone socket. You should replace the sockets in pairs. Before purchasing new sockets, you will need to remove the old ones first.
Disconnect the power supply to the fluorescent light fixture. The circuit breaker for the fixture is in your home electrical panel box. If you have a fixture that plugs into a wall outlet, unplug the power cord from the outlet.
Remove the light fixture cover from the fixture. Most covers snap on and off. To remove the cover, grab the cover on both sides and squeeze to release the cover from the fixture. Some fixtures use two screws on each side to secure the cover. Remove the screws with a Phillips head screwdriver and pull the cover off of the light fixture.
Grab each end of the fluorescent tube with your fingertips. Roll the tube out of the socket until the tube disconnects from the socket. Pull the tube away from the fixture and set the tube in a safe place so that it does not get broken.
Remove the screws that secure the light fixture end caps to the fixture with a Phillips head screwdriver. You can now pull the tombstone socket off of the end of the light fixture. Some sockets snap into the bottom of the light fixture. To remove, insert a small flathead screwdriver between the base of the socket and the light fixture and pry the socket out of the fixture.
There are four wires that attach to the tombstone socket. Wrap a small piece of masking tape around each wire and write the location of each wire on the tape with a pencil. Cut each wire as close to the socket as possible with wire cutters.
Take the tombstone sockets with you to the hardware store. You want to purchase sockets that are the exact same size and configuration as the current sockets.
Strip ½ inch of insulation from the ends of each wire with wire strippers. Refer to your labels where each wire goes in the socket. Insert the bare wire into the appropriate terminal in the socket. The terminals have barbs inside that grab the wire and hold the wire in place.
Set the socket back into the end of the light fixture and push the socket in until it locks in place. Position the fixture end caps back on the fixture and secure with the retaining screws.
Place the fluorescent tube bulb into the tombstone sockets until the fixture locks into position. Snap the light fixture cover back onto the fixture. Turn the light fixture's power supply back on.