Kaitlyn Jaffke, marketing and sales coordinator, walks through the "laser swamp" of the "13th Floor" haunted house in Denver, on October 19.  America's Haunts, a trade association, estimates there are 1,200 large-scale, for-profit haunted attractions in the US plus another 3,000 haunted houses operated by charities that open for only a day or two every year. The commercial attractions collectively bring in from $300 million to $500 million annually. Reuters/Rick Wilking