I remember this article and built one of these sometime around 1999. Unfortunately, I don't recall the source. I think it was in either Magic Magazine or GENII, circa '90s.
I still have the light switch trick sitting on my desk at work. I built it into a small round tin that I got from the craft store. The tin has a seam that runs down one side. I like to hide the seam at first, making selection of the right switch more "difficult," then later let the spectator notice the seam. They usually fall for it like a bent card corner...