The Room, published in 1942 in Unknown

“The Room”
by L. Ron Hubbard

Publication date: April 1942

Original publication: Unknown Worlds

Genre: Fantasy

Story description: One day Uncle Toby goes into his very own private den—a room filled with strange objects that have even stranger properties—and he is never seen again.

Currently available as part of the Stories from the Golden Age series, in the title Danger in the Dark.