I had this idea to have a Dr F switch in my house. However, it would be exposed electrical, right? Would there be a way to simulate that kind of switch?
The one breen2057 put up is what I was thinking. It's basically something you install over a standard switch. Going to a rocker light switch makes it really easy to build a fake switch over it. As Moviefreak said lots of people sell stuff like that. It's not hard to make, but there are so many options already out there. If I were making it I'd add some unconnected wires to make it look more real.
Remember when you use it to do your best Maniacal Laughter as tradition requires. Thunder and Lighting would be a nice addition but hard to arrange in advance.