The 1977 horror film The Sentinel is the answer.
Ironically, one of the few people who appeared in this movie who wasn't a star or didn't become a star, WAS the star, Christina Raines, who is fine as a young model looking to rent a New York City apartment. This movie has legitimate scares. And a far above average story.
The Sentinel. Magnificent. Soon after Raines moves in the weird stuff starts going down. And I mean weird stuff.
Beverly D'Angelo gets to it for no good reason at all other than it being Tuesday. These neighbors are weird. Did I say that?
One of the more chilling scenes I can recall in cinema history culminates with this little bit of nicety. Here's the deal: it's the gateway to hell. Says that on the box. This movie in entertaining in multiple ways, but the last ten minutes BRINGS IT...
Gateway to Hell opens, these freaks come spilling out. And yes, these are real human oddities. You will crap yourself.
Lesson of The Sentinel. If someone offers to rent you an apartment in New York with antique furniture and shelves full of ancient books for $400/month.... run.
February 21, 2013 update: Google tells me this is one of my most popular blog entries, and it's almost entirely due to people thinking they are going to see dirty pictures of Beverly D'Angelo. You is some creepers out there in cyberland, but keep it up.