Most homes, regardless of how well they were built, have flickering lights and it's really not all that unusual of a problem in most cases. Some common causes of flickering lights are high load appliances kicking on such as pumps, air conditioners, electrical heaters running on a thermostat, water heaters and even clothes dryers. If you notice your house lights flickering when these appliances are starting a cycle, then there's usually nothing to worry about. If, however, you notice that your house lighting is flickering abnormally or smell a burning plastic smell then you may want to have your electrical checked out by a certified electrician at your earliest convenience. Unless you have DIY electrical experience, you may want to let a professional troubleshoot your flickering lights.