The pumpkin is, IIRC, put up by someone in the neighboring house for Halloween.
I had a school bus driver once who was very into ghostlore (she was a bit weird) and she told us that apparently there had been a dispute between the Indians and the Dutch settlers and someone had been murdered and the ghost haunts the road at that spot.
She was a bit of a nut, as I said. That could be a known story or not, no idea. But I’ve never heard anything about avodah zarah.