The Shrinking of Treehorn, published in 1971 by Holiday House, New York, was written by Florence Parry Heide and illustrated by Edward Gorey.
In this tale young Treehorn has begun to shrink in size, and while the adults take note, nobody is concerned enough to do much of anything about it. Treehorn eventually shrinks small enough to find an unfinished board game under his bed which is the cause of his unusual problem. He realizes he must continue the game to grow back to his normal size. This accomplished, he packs up the board game and puts it away. This story predated Chris Van Allsburg's Jumanji by 10 years, which features a similar theme, even though the board game is not nearly as destructive as Van Allsburg's.
The illustrations for this volume are quite unique. The borders on the wall paper and the kitchen cabinetry in Treehorn's home is very unusual, even for Mr. Gorey! On the kitchen cabinets, graphic oriental hinges frame the cupboard doors. Treehorn's school principal has a large piece of very modern art on the wall of his office, and the clothing for Treehorn's mother and the principal's secretary is "way out"! Very early 70's!
One thing I found amusing in the writing of this story is a small detail. While at school, Treehorn tries to get a drink in the hall from the "water bubbler". I noticed on the flap copy that Ms. Heide lives in Kenosha, Wisconsin. I am originally from Milwaukee, WI (about 30 minutes North of Kenosha). As a youngster my friends and I referred to water fountains as "bubblers". This is a regional Wisconsin slang term that is rarely used by people outside the area. Even my sister, who lives in central Wisconsin, says the term is not used where she lives.