Inspection: Always inspect your lights each year. Look for broken or frayed wires, and broken or loose connections to avoid potential fires or shocks. If you find problems, replace or repair.
Weather: Wait for a dry day to install (and remove) electrically powered outdoor decorations.
LEDs: Switch to LEDs, not only for efficiency, but also for safety. You can use up to 25 strings connected end to end into one wall socket without overload. With incandescent strings, limit each socket to three strings.
Cords: Use extension cords rated for low temperature and outdoor use when setting up outside displays. Keep connections off the ground and hang sockets downward or seal connections to prevent water from getting in.
GFCI: For best protection, plug outdoor lights and decorations into outlets with ground fault circuit interrupters (GFCI).
Power lines: When decorating outdoors, look for power lines. Never throw a string of lights or other decorations into trees near power lines. Keep ladders, equipment and yourself at least 10 feet away.
More holiday electrical safety information:
Electric Safety Foundation
LEDs: Energy-saving LED lighting is much more efficient than old-fashioned incandescent bulbs. They also last much longer, have a lower temperature and resist breakage.
Timers: Put timers on your outdoor displays to automatically shut them off overnight.
Calculate: Learn about holiday lighting and decoration costs with our calculator.