Making an unlikely debut in More Fun Comics #52 (1940), the decidedly not fun murder of detective Jim Corrigan lead to his spiritual encounter with The Voice, a Heavenly entity most interpret to be God Himself. Corrigan was refused entry through the Pearly Gates and, instead, assigned the minor task of "eliminating evil from all the world". When he wasn't vanquishing criminals and supernatural threats in the eerie guise of The Spectre, Corrigan continued to maintain his human appearance and occupation as a detective.
As such, Corrigan's former humanity continued to express itself even when he assumed "ghost mode". This scene from his early days with the Justice Society of America (from All-Star Comics #9, 1942) shows a Spectre who's an enthusiastic team player and still very much a part of the human world.
Within the context of 1940's (Golden Age) comics, this was about as deep as it got when it came to Corrigan's ghostly quasi-existence. After all, the brief plot-driven stories of early superhero comics left little room to fully develop characters or to explore more emotional territory. Because of this very straightforward style of storytelling, the potentially powerful story of this near-omnipotent being still pretending to be a human was never really explored until many decades later.
During an investigation of the Ghostly Guardian's past in The Spectre #20 (1994) Professor Nick Hazzard interviews several of the Spectre's old Justice Society teammates. All of their stories were fascinating, but the best and most haunting of these recollections came from Carter Hall (Hawkman) and his wife Shiera (Hawkgirl) as they told the poignant tale of Jim Corrigan's fading humanity and his final departure from the affairs of mankind.
(click on the panels for a larger view)