In the Ghost Hideout, there's a sequence in the very first mission, Quell the Bandit Threat, where you get stabbed in a cutscene and taught how to use the Defibrillator. After this, you exit the 'killing room' into a hotel room-like area, clear out all the bandits and head to the back of the room toward a painting on the wall. Between the TV and the painting in this room, you can open up a section of wall. Behind it is a pixel Wolfenstein room with the Wolf Goblet inside. You can sell it for 150 dollars.