This Christmas, avoid adding too many strings of Christmas lights to any one circuit that would cause a circuit overload and a possible electrical fire. Too often, we are tempted to be like the Grizzwalds and add as many Christmas lights to our Christmas trees, windows and roofs of our homes.
The problem is that circuits can only handle so much and the massive bulk of cord connectors protruding from the outlet itself becomes a possible fire hazard. When the weight of the plugs draw the plugs away from the outlet, it often exposes the contact terminals of the plugs.
By checking the box that the lights came in, you'll be able to learn the amperage draw of the light set. Most receptacle circuits in your home are rated for at least 15 amps and generally are 20-amp circuits. The rule of thumb is not to load a circuit over 80%, meaning a 20-amp circuit's safe useage is 16 amps.
Likewise, by checking the Christams lights packing box, you'll see the maximum recommended end-to-end connection of sets of lights. Adding too many will overload the wiring associated with the Christmas lights and could start them on fire.