The Independence War Paper Models site has some very nice — and free — paper models of starships.
This free paper model of Disney’s Haunted Mansion is a tour-de-force. Even if you don’t want to download it, you need to take a look.
Germy’s World has a paper model for making your own dungeon, but what is more interesting is Victorian Cellar model that accompanies it. It’s perfect for gothic horor games as the lair of a monster, or mad scientist or cult.
Ravensblight has a free paper model of a hearse and coffins. Because you can have your printer resize these, they can be used for any number of scales and games.
Add a creepy cemetary to your tabletop with this paper model from Ravensblight. The file is a pdf, so you cna resize it using your printer’s control panel to make it fit whatever scale you need.