For zombie game inspiration, you can download and watch George Romero’s 1968 classic horror film, Night of the Living Dead for free.
Warpspawn games has a vampire hunting game called Methuselah designed to be played on a chessboard with a custom set of cards. One side plays Dracula and his minions, the other the vampire hunter and his assistants.
I think that some of the ideas could easily be lifted for use in more traditional miniatures games.
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.
Assault on Innsmouth is a set of free wargames rules for involving the Lovecraft Mythos. The players are government forces taking on the horrors in Innsmouth. The forces of the mythos are run by the system. The rules are a heavily modified version of the Two Hour Wargames system. There are also expansions at Board Game Geek.