First off....I don't have a link but i saw this "light switch" on a youtube video. He did not have a save or schematic so i took it upon myself to try to figure it out. This is what i came up with. You flip the switch and blocks drop to reveal a lightstone behind the block that dropped. I made a tunnel( just like the video...MAN I WISH I HAD A LINK) to show how it works. I like it and it can be used in so many ways. Next project housing lights...