Pierce never spoke about what or who he saw, simply because paranormal activity was a highly debated issue and obviously not scientific - therefore, it didn't make much sense (nor was it good for his credibility) to go around explaining that he saw ghosts all of the time and the images were always horrifying. Very few people looked picture perfect right when they died.
But this was different. His niece was in a graveyard at night. This wasn't some ordinary situation. She talked to them too, perhaps?
"I do talk to them," he said, watching her. "I always have. Not something I've told anyone though." There was an unspoken undercurrent of 'so you probably shouldn't either.' And he waited expectantly for details about what the fight with his son entailed.