Sadly, not the story of an otherworldly rebellion against the ghostbusters, Ghost Army instead tells the equally outrageous tale of fighting Nazis with inflatable tanks. Also, it's totally based on a real thing.
Warner Bros. is developing the movie, with Bradley Cooper (American Sniper), Todd Phillips, and Andrew Lazar producing. Henry Gayden (Earth to Echo) is set to write the script, which follows artists, designers, and ad men who get recruited by the army to deceive the Germans about their numbers.
The story is based on a recently published history book entitled "The Ghost Army Of World War II: How One Top-Secret Unit Deceived The Enemy With Inflatable Tanks, Sound Effects, And Other Audacious Fakery" by Rick Beyer and Elizabeth Sayles.
Ghost Army has no release yet, however given how early it is in the developmental process don't expect it for a few years. If you'd like to know more about the true story, there is also a documentary, also titled Ghost Army, where you can learn more.