Seeking Author and Title of Story

There's a vampire short story I've been trying to track down. A man gets a letter telling him that a vampire will call on him on a particular evening, so kindly remove all mirrors, crucifixes, etc. The man thinks it's a great gag. It's not, of course-a real vampire shows up and prepares to chomp down. The man desperately holds up a cross, but the vamp just shrugs it off, saying, "You really don't get it, do you?" Then the man pulls out his wallet and offers up all his money. The vamp shrieks and departs at the sight of what is truly sacred to his victim.