A firearm used by ghosts, I guess. As we here all know, the freedom-haters love their pejoratives, so 'ghost gun' goes in right alongside 'saturday night special', 'pocket rocket' and, of course, our favorite -- 'assault weapons'.
"Ghost gun". Oooooh, scary. BAN IT!
I would wager that California would have less of these to worry about (if they are indeed even worthy of such) if they didn't nurture a culture that tends to favor inner-city black drug gangs, millions of illegal aliens, and other societal ills.
The latest statist meme pushing national registration.