10 years ago my young child had fairy lights hung up in her room. They were really pretty and not too bright. However she didn't really have a way to turn them on/off without unplugging them. So, I remembered the "Clap on!" device from years ago and thought it would be the perfect solution.
It turns out that they are hard to find and very expensive ($30) for what they are. Even if you can find them it's hard to tell if its an original unit or some super cheap knockoff that might burn your house down. :(