“Grimm, Ghost Spotter” is a character from the Iger studio, published in Bomber Comics #1 (1944), from Elliott Publishing Co. This first episode also appeared the year before in Harvey Comics’ War Adventures Comics. I don’t know why the same Grimm story showed up the next year in a wholly different publication, but a guess is that Harvey had hired Iger to do some features, and then there was some problem, so Iger took Grimm the Ghost Spotter back and put him in another comic book.
The ghostly manifestation in the story reminds me of the later ghost tales from ACG’s line of supernatural comics (Adventures Into the Unknown, Forbidden Worlds, etc.) where ghosts are more of a physical presence than something diaphanous hovering between the afterlife and our world. Back here in the land of the living, I’d be grim, too, if I were facing apparitions like this.