haunt lighting

I watched Terra's video and i just loved that shaking werewolf and how it activated and then had a strobe on it. I know she used like a computer set up and i really don't wanna go that route. I basically want to have a strobe light (or light in general) be able to kick on as tot's walk past it...

First i wanna say sorry if it seems i'm posting a lot of questions. It's only my second year home haunting and haunt season is coming up! Last year i put props and stuff in my dark maze in my garage but problem was after i did it you couldnt see any of the detail. So i was thinking this year to...