Holiday Lighting Safety | Electricity Guidelines
• Never throw holiday lights or other decorations into trees near power lines.
• Be especially careful when working near power lines attached to your house. Keep ladders, equipment and yourself at least 10 feet from all power lines.
• Use only lights that have been safety tested and have the UL label.
• Before use, check each light string for broken sockets, frayed cords, or faulty plugs. Replace damaged strings. Always unplug light strings while replacing bulbs.
• Outdoors, use only lights, cords, animated displays and decorations rated for outdoor use. Cords should be plugged into outlets equipped with GFCIs. Use a portable GFCI if your outdoor outlets are not equipped with them.
• Do not staple or nail through light strings or electrical cords, or attach cords to utility poles.
• Don’t string together more than three standard-size sets of lights.
• Make sure extension cords are in good condition, are UL-approved and rated to carry the electrical load you will connect to them.
• Match plugs with outlets. Don’t force a 3-pronged plug into a 2-pronged outlet or extension cord.
• Do not overload outlets. Use surge protector strips if multiple outlets are needed.
• Keep electric cords away from high-traffic areas, and don’t run them through doorways, or hide them under rugs or carpets.
• Don’t let children or pets play with light strings or electrical decorations.
• Place fresh-cut trees away from heat sources, such as heat registers, fireplaces, radiators and televisions; and water frequently.
• Always unplug lights before going to bed or leaving your home.
Source: http://safeelectricity.org