Amid the many masquerades and costume balls that accompany the Halloween season, there is one classic attraction that San Francisco has been sorely lacking: the haunted house. Not so this year. The Haunted House of Horrors is designed to scare the wits out of anyone, with hundreds of life-sized ghosts, ghouls, demons and monsters, as well as two different mazes, and "25 chambers of horror." The event includes a cast of 75 actors, boasts $175,000 in decor, and takes place in the perfect venue, the Old Mint. For those who haven't noticed it, the Old Mint is that large, empty-looking granite building on Fifth St. between Market and Mission. It was built in 1874, and the front steps are often populated by a brand of ghoul native to the Tenderloin. As we said, the perfect location. To be clear, organizers insist that this is more than just a haunted house. "This is a live horror movie experience," says their website. There is a story and plot, and participants will be "running for their lives" in a bid to kill the monsters and save the world. If they dare.