In Strange Adventures #62 (September 1955), an organization of inter-galactic space travelers rescues a human from Earth and reveal themselves as the “Watchdogs of Space”, a group that patrols the spaceways and helps from the shadows. They recruit this human into their organization.
The Watchdogs sounds remarkably like the Green Lantern Corps, even down to the idea that any entity from any world can be recruited. Sadly the Green Lantern resurgence is still a few years away at this point.