There is 1 Dead Ghost to be found in Anchor of Light. They can be collected on any mission or during a patrol. Each Ghost can only be collected once per account.
Head for the large building, the satellite array. Head up onto the platform.
When you make it to the top of the ramp, look for the gap n the left-hand side of the suspended metal beams:
Jump up onto the crate at the base of the pillar to your left. Turn to the right, toward the center of this structure. You can either Double Jump up or Sprint Jump to reach the next beam:
Just look toward the side you came in on. You will see the Dead Ghost