Haunted Dimensions has a free paper model of the spooky entrance gate outside Disney’s Haunted Mansion.
Invisible City Productions offers Cthulbeque, a game in which players compete to put the most Cthulhu themed dishes in their serving area.
Savage and Soldier magazine has a good introductory article on the US v Philippine Insurgents in the early part of the 20th Century. It’s always struck me as a period that would make for a good game.
The Haunted Dimensions site has paper models of three small crypts. The only downside of these is that the back of the crypts are defaced with site advertising. Still, there’s also a brick wall there that you can paste the crypts up against.
Stormed At With Shot and Shell is a set of free miniatures rules for playing games set in the Crimean War. They’re designed for 15mm figures.