how to fix your christmas lights

Oh, well, you see, there's this special thing called a "light tester" that you can use to see which bulbs are bad and which are still good. You just plug the tester in where the lights are supposed to go, and it'll light up if the light bulb is good, or make a noise if it's bad. Then you just replace the bad ones with new ones! It's really easy once you know how to do it.