Today I found a paper posted to a bus stop that used "paster" rather than "pastor." It was definitely religious (and used as a person's title). At first I assumed it was just an embarrassing misspelling, but then I remembered making a similar assumption with imposter/impostor, and now I'm all curious. Is it acceptable in some situation or variety of English to spell it "paster"? I searched Google but it wasn't particularly useful beyond dictionaries listing no alternative spellings for the word... which just might be my answer, but I thought I'd ask this community to make sure.
EDIT: Embarrassing (and amusing) misspelling it is. Thanks to everyone who commented!