It is estimated that as many as 63,000 people died as the sanatorium. Those deaths coupled with the reports of severe mistreatment of patients and highly questionable experiments and procedures are ingredients for a haunted location.
Ghost investigators who have ventured into Waverly have reported a host of strange paranormal phenomena, including voices of unknown origin, isolated cold spots and unexplained shadows. Screams have been heard echoing in its now abandoned hallways, and fleeting apparitions have been encountered.
In the article, Those That Linger, by Keith Age, Jay Gravatte and Troy Taylor, you can read more about these investigators' experiences.