How do you build a thrilling Halloween hay maze? For years, Dominic Grossi sketched out the adventure on paper. But with 1,200 hay bales, the task was tedious. Now he designs it in the field, across from Stafford Lake. Starting at the maze’s exit, he builds several routes toward the middle. Then, bale by bale, each path but one is blocked by dead ends. The hay will be useful after the holidays to feed his…