Ghost Hunter

Ghost Hunter is a special perk

Obtaining
Talk to Dog after he has killed and devoured one of the ghost people. Follow the Speech path starting with "I watched you devour one of the ghost people". The perk will be awarded once the Courier asks Dog "How do you do it?"

Alternatively follow a dialogue path that requires the Cannibal perk, and he will give the perk soon after he is met.

Effects
Ghost people are much more likely to die outright, even without being dismembered or disintegrated. Once this perk is in effect, when ghost people are reduced to zero health, one of their limbs will explode automatically at random.