Hey guys and gals! Here is my 100% Achievement Guide for Infliction!
You will be in a bedroom, once you walk out you get transported to a filthy looking hallway.
(Quick point, if you need another picture of the ghost for the "Supernatural Investigator" achievement, go right to the end of this hallway and take a picture of a slightly jarred open door).
In the middle of this hallway is double doors you need to go through. The right hand side of thise room has a vent to crawl in and you go sliding down.
You will then wake up in a room with a big huge looking mofo with a meat cleaver in plain sight in the next room.
Walk over the broken glass to get his attention and to come towards you, and as soon as he starts coming, crawl back through the vent behind you, into another room and on the left when you get out is a red button, push that quick and achievement unlocks!
Go to 39:50 to see how and where this unlocks.
Hope This Helps!