My Mother-in-law is certifiably crazy.
She wanted a way to write messages for my wife and I, if we aren't home. So we bought a dry erase whiteboard and hung it in the kitchen. We bought a new package of dry erase markers and set the unopened package on the ledge on the white board. Yesterday work called for me and I was out in the yard.
My MIL opens the package of dry erase markers, used one to scrawl a message on the cardboard marker package. She then propped the package, with the message, on the ledge on the white board.