The New Yorker has a great little epistolary fiction story, relevant to Halloween, here on their site: http://www.newyorker.com/humor/2011/10/24/111024sh_shouts_semple?currentPage=all

What I like about this is a) how things slowly go awry and b) how e-mail has created a world in which most of us have had experiences somewhat like the ones described in this story.