crazyforgoofy,
If you're trying to run the lights around the whole house off one plug, you're overloading at least the first set and possibly one or more others. Even though these things have sockets at the end to add on more lights, they are usually only good for about three sets. Unless you have a very small house, I'm guessing you've joined a lot more than that together. You will need to find alternate places to plug into about every three or four strings of lights. The box they came in should tell you how many you can string together.