By - Greebous
"A crew of Martians overhears a radio broadcast of Orson Welle's \_War of the Worlds\_ coming from Earth, and, thinking the Martian fleet is attacking Earth, they land their broken-down ship in a backwater mid-American town. As luck would have it, they land on Halloween and get mistaken for trick-or-treaters. Comedy ensues as the Martians try to get taken seriously."
This seems like the plot to Space Invaders from 1990.
Maybe [Space Case - Edward Marshall, 1980](http://www.librarything.com/work/273047/reviews/163284542)