During the shoot, Wolfhard and his fellow cast members decided to explore an old mansion in Toronto where they were filming. The young actor distinctly remembered spotting a figure on the top floor—a man dressed in black, seemingly working on electrical equipment. Assuming he was just another crew member, the kids didn’t think much of it at the time. However, later on, they were surprised to learn that no one on the crew knew who the man was, and no one ever saw him again.
Speaking with People Magazine, Wolfhard reflected on the experience, saying, "I’ve been in a lot of supernatural movies and TV shows, but ironically, I’ve never really seen a full-on ghost.” However, this unexplained encounter left a lasting impression, with Wolfhard admitting it was a spooky memory from his early career.
Though he laughed off the possibility that it might have been a prank, the experience was an unsettling one for the young actor, who has since starred in other horror favorites like The Turning, Ghostbusters: Afterlife, and the animated The Addams Family.