“I didn’t move into this house thinking I was going to move into this house full of ghosts and write a haunted house novel,” author Aimee Pokwatka, 45, told The Post. But that’s exactly how things went. In 2019, she and her husband, Jason Kyle, bought a Westchester home dating back to the 1750s for themselves and their two sons, then ages seven and nine. The spiritual encounters Aimee Pokwatka had after buying her Lewisboro, NY, home inspired her new novel. Aimee Pokwatka With historical features like a “coffin door” — leftover from the days when people held funerals in their living rooms — a dangerously steep staircase in the back and an underground tunnel that cut through the property, the Lewisboro, NY, home was strange from the start. The idiosyncrasies were a selling point for Pokwatka. “My dad, when I was growing up, was obsessed with Bob Villa,” she said. “We watched ‘This Old House’ like it was our cartoons.”  Then odd things started happening.…