With the use of a projector, you can turn a Halloween party, a bonfire, or a heated pool party into something quite visceral!
This photo above shows a Halloween party set up I made in 2009. I projected a Brothers Quay "Street of Crocodiles" creepy animated doll video onto the side of a shed where I had placed baby dolls at various distances to interact with the movie. A mannequin can work well for such things or even utilizing texture surfaces, pumpkins, and a scarecrow.
Here's a reasonable projector -
Brothers Quay are creepy stop animations with scary music -
Fabric for making projection screens -
An outdoor theater setup doesn't have to just be a screen. You could project a movie onto your garage for Halloween - like this -
How to make an outdoor theater
Sometimes interactive horror watching is the best during this season -
Interactive movies are one option - a setting that makes watching the movie especially frightful. Imagine floating on a raft in a lake while watching Jaws???
Could you watch "Halloween" with a man in a Michael Myers mask and a knife walking silently around the place, hovering, watching, pacing....
What if admission to see "Phantasm" meant putting your hand in a box ---
You might want to consider the use of ground fog machines to add a new component to watching "The Fog"
How about if "The Birds" was shown with a line of fake crows atop of the screen staring down at the audience?
Nosferatu might be ideal with some heavy velvet drapes tied back on either side of the screen.
Psycho begs to be watched on a white curtain on a curtain rod....
AtmosFearFX has projection videos down pat for the season. If you don't want to do a movie but want spooky images to be among your guests, you might consider some of the amazing videos. They have everything from faces you can project on Jack O'Lanterns to 80s slasher, ghosts, zombies, and more!
Night of the Living Dead