Project Immortality

Chris wakes up in his bedroom crime scene and quickly realizes that he is now a walking-talking corpse as well as a ghost who can't touch anything or be seen by anyone! 

Along with a knife at the crime scene, there is a also syringe that belonged to Chris's recently disappeared girlfriend - Kacey. With no other leads, the ghost and zombie conclude that they can only find out where Kacey went if they manage to solve their own murder.