Fall for me as a teenager meant football games, homecoming dresses – and haunted houses. My friends organized group trips to the local fairground, where barn sheds were turned into halls of horror, and masked men nipped at our ankles with (chainless) chain saws as we waited in line, anticipating deeper frights to come once we were inside. I’m not the only one who loves a good scare. Halloween attractions company America Haunts estimates Americans are spending upward of US$500 million annually on haunted house entrance fees simply for the privilege of being frightened. And lots of fright fans don’t…