Check light strands for worn insulation, bare wires, lost or broken bulbs, loose connections, or broken plugs and sockets.

A string of lights with any loose bulb connections should be replaced immediately. If a bulb is burned out, unplug the strand of lights and replace the bulb with a new bulb of the correct wattage as specified by the manufacturer.

NEVER try to bypass an empty socket with aluminum foil or other objects. Instead, place a new bulb in the socket or replace the complete set of lights.

Always purchase lights that are labeled by a testing laboratory (such as "UL") and follow the manufacturer's instructions for use.