Most haunt walls are made up of 2x4 stud frames with 1/4" - 3/8 sheeting. It can get pricey considering making up several rooms. However, i make some walls with 2x2 studs and foam sheeting, sprayed with stucco type concrete. 6 mil black plastic sheeting works too, 20x100 ft rolls run around 90 bucks at lowe's. U might think about a large tent also, however, in ohio anything over 1000 sq. ft. must be inspected by the fire marshal.