Miracle Watt or MiracleWatt and other types of devices like it, prey upon both widespread scientific illiteracy and an intrinsic desire to save money. Without boring you with the details, these plugin boxes do not change the true power consumption in your home, rated in watts. Over the years, many people have not only tested these devices but opened them up to only find a capacitor and an LED light inside them. And it is easy to get testimonials on how they work, as electrical power consumption typically declines as we move into spring. Few consumers track their electrical usage hour by hour over the winter either to have reliable data for comparison.