Anyone familiar with Flat Stanley? I'd never heard of this until recently seeing it in another group.
Flat Stanley is a 1964 children's book written by Jeff Brown. It is the first in a series of books featuring Stanley Lambchop.
Stanley Lambchop and his younger brother Arthur are given a big bulletin board by their father to display pictures and posters. He hangs it on the wall over Stanley's bed. During the night the board falls from the wall, flattening Stanley in his sleep. He survives and makes the best of his altered state, and soon he is entering locked rooms by sliding under the door, and playing with his younger brother by being used as a kite. One special advantage is that Flat Stanley can now visit his friends by being mailed in an envelope. Stanley even helps catch some art museum thieves by posing as a painting on the wall. Eventually, Stanley is tired of being flat and Arthur changes him back to his proper shape with a bicycle pump.