Position: Hallway or in between rooms
Nothing is simpler than this classic bit of creepiness. A dim hallway has clear fishline of varying lengths hanging from the ceiling. The guests can't see them, yet they're getting touches on their faces, light, brushing touches. If there are plastic bugs on the walls and perhaps a hint of moving light, those bugs will seem to move, thoroughly creeping those who cannot stand the thought of bugs.
An alternate and popular alternative is to have a room with a strobe and flourescent dots painted on a black background, along with hanging balls in similar flourescent colors. This is very disorienting and it is possible for an adult in black with flourescent dots to hide in the room and create scares as well.