Ghouls and goblins and assorted other fright-makers will fill the Ventura Jaycees' 21st annual "Factory of Terror" fund-raiser at the Ventura County Fairgrounds, 10 W. Harbor Blvd., Ventura. The sizable haunted house--all 5,500 square feet of it--has eight differently themed scare chambers. Visitors are guided through them all and then left in a darkened maze to fend for themselves. The faint of heart need not worry; emergency exit doors are provided. The house offers Halloween entertainment for the entire family, with an emphasis on children and teens. Hours: 7 to 9:30 p.m. today and Sunday through Tuesday; 7 to 11 p.m. Friday and Saturday. Tickets are $7. Proceeds benefit high school club and group activities. Information: 656-1260.