Protection
by Robert Sheckley
Galaxy Science Fiction (April, 1956); UK No. 39 (June, 1956), pp. 54-63.
One of those technically insubstantial Sheckley short stories that nevertheless skims along with sufficient comedic insouciance to qualify as a good read. The protagonist accepts an alien protection service, just because it’s free, but in doing so brings about his own undoing.