There is 1 Dead Ghosts to be found in Firebase Rubicon. They can be collected on any mission or during a patrol. Each Ghost can only be collected once per account.
Ghost 1[edit]
Get into Firebase Rubicon:
Head over to the left and start over the walls. You are looking for this lighting unit:
Go between the lighting unit and the crate and into the dust. This leads to a very well concealed cave.
Follow the cave to its end. There you'll find a tree. Look along the left-hand side and behind it to find the Dead Ghost:
