When I get the gumption to build my own “dream house”, I’m going to make sure it has plenty of secret passageways and the like. I started this trend a couple years ago in my current home by simply placing a conspicuous piece of paper in a slot between two bricks in my kitchen. Observant people with a bit of curiosity and a dash of daring will pull it out to see what it is:
I think this is quite hilarious, because I know the paper has been read several times yet I’ve never once been asked about it. I just hope they get the joke and chuckle as they put the paper back in its place.