A skeptic visits a Spiritualist camp that’s been peddling communication with the other side for more than 100 years.

Off in a Florida wilderness of scrub palms and dense oak trees draped with Spanish moss—about 50 miles northeast of Orlando’s theme park corridor, and even closer to the busy beaches of Daytona—is Cassadaga, a blink-and-you’ll-miss-it exit off Interstate 4.