The Phantom Stranger makes his debut in DC’s Phantom Stranger #1 (June 1952) and was created by John Broome and Carmine Infantino. The character is unnamed and not given an origin, simply appearing across 3 different stories of people encountering supernatural events. In each story, he debunks the supernatural aspects as hoaxes and solves the crimes with the use of a mysterious device called a “conjure flash”.
Although he mysteriously arrives and disappears, no other evidence of supernatural powers are present for him. It’s not until much later (15 years!) that the character was made into one of DC’s most powerful supernatural characters, much like The Spectre.