Lester del Rey's "Dead Ringer" (short story, creepy, free)

Plot idea is rather common;  I've seen more than one story like this of Kuttner alone.

Story summary.

Most of the story is a creepy one - a man has convinced himself that there are aliens among us, aliens in the shape of humans, aliens who intend to take over earth. And that these aliens cannot be killed; they get resurrected. Of course, he's unable to convince anyone.

There is a surprise ending, but may be I've already spoiled it.

Fact sheet.

First published: Galaxy, November 1956.
Download full text from Project Gutenberg, Manybooks, Feedbooks.
Rating: B. 
Related: Stories of Lester del Rey.