Back in the days before electricity, your lighting was generally provided a fireplace or candle (unless it was daylight out, that is). When you finally went to sleep at night, you’d generally just blow out the candle. If you want to recreate some of that 19th century magic, you can get a light switch that you turn off in the same manner.
That’s right, someone created a light switch that is controlled by your breath. This one isn’t meant to be installed in your wall, but rather it sits on your night stand (or anywhere, really) and lets you control a light from there. It can be used like a traditional light switch, or you can blow on it. It’s rather silly, but for $14, it might make a fun present for a small child.