Seaford Historical Society president Teresa Wilson wasn’t a real believer in ghosts or the supernatural. But that changed last spring when Phantom Detectives LLC, at the society’s request, targeted Gov. Ross Mansion in a quest for proof of paranormal activity. “I’m going to tell you, I walked in thinking, ‘Oh, there’s no such thing as this.’ And I walked out saying, ‘I am a believer.’ That’s how wonderful it was,” Ms. Wilson said. “I saw everything. I’m a believer.”