The Pink Refrigerator by Tim Egan

From the back of the book:
Try to do as little as possible. This was Dodsworth's motto. one morning, on his daily trip to the junkyard, he discovers a pink refrigerator. There's not much to say about a pink refrigerator, except this one had a note on it. The note said, "Paint pictures." And so Dodsworth did. The next day, a new note appeared on the pink refrigerator. And the day after that, and the day after that.