Field of Screams has been running haunted attractions on a Mountville, Pennsylvania farm since 1993. Over three decades, the operation has developed a rhythm that regulars understand, and first-timers usually learn the hard way. Here is what to sort out before you buy a ticket. 1. September is the underrated month The single most common piece of advice from people who go every year is to stop treating October as the only option. Early season nig…