Although you may have never heard of Ghost, she was/is a pretty cool character. Ghost was created in 1993 for Darkhorse Comics by Team CGW (Team Comics' Greatest World) which was comprised of Darkhorse creators Mike Richardson, Randy Stradley, Barbara Kesel, Jerry Prosser and Chris Warner. And "Ghost" is considered to be one of the best written comics out there.

The book is about Reporter Elisa Cameron who is apparently dead. I say "apparently" because...well..in this book nothing is really as it seems. As a "Ghost" Elisa can pass through solid objects (ghosting) and teleport. She also carries two Colt 45s and looks a lot like the old pulp heroes of the 30s. Fantastic cover art by Adam Hughes and Terry Dodson added to that image quite well.
Although Darkhorse isn’t "mainstream" Ghost has managed a few high level cross-overs. Her first was with another Darkhorse character Barb Wire. Then she teamed up with The Shadow, Batgirl (Cassandra Cain), Hellboy and The Mask.