Carbon Copy

Story, first published: Galaxy Science Fiction, Dec. 1957

A greedy realtor is approached by a Mr. Steen (he must be an alien - he is wearing his shoes on the wrong feet), making him an offer no real estate agent can refuse. For a ten percent fee, Homer can lease the same fifty houses over and over again when his clients mysteriously move away, leaving their houses empty. Homer investigates and finds that his clients have moved into dimensional extensions or "carbon copies" of the first house. Homer is rapidly becoming a wealthy man until another alien shows up. The second alien informs Homer that the housing project will be destroyed and that Mr. Steen is an alien practical joker who came to Earth with the wrong plan - something else is in store for us. The aliens commit ritual suicide and leave Homer holding the bag, the victim of a final prank - the bags are full of worthless $20,000 bills.

Ewald, Robert J.: When the Fires Burn High and the Wind is from the North, p.55-56