Long ago, I placed an ordinary light switch outside the bathroom for the convenience of the family. Over the years it became apparent that the said family tended to leave the light on more often than not, which made both me and my wallet quite grumpy. :-(
I have an attic area that is only used for storage. I have a few fluorescent lights to illuminate it. I noticed that the lights were sometimes left on. The same type of switch has solved that problem.