While on the Coming War mission, continue up until you reach the elevator. When the second Cabal gets Taken you'll see a dead ghost among the Taken energy.
Phobos 3
Once you get to the Aerodrome, jump down onto the platform below you. Look for a few pipes that lead to the dead ghost.
Devil's Spire 1
A ghost is located in the rafters on the Cayde's Stash mission. Stop right before the elevator near Devils Spire to jump to it.
Devils' Spire 2
In the same area as the previous one, climb to the top of Devil's Spire when you move the bridge. Jump up until you can get the ghost
Devil's Spire 3
At the end of the Cayde's Stash mission a ghost will be on a pipe on the outer edge of the area.
Bunker War 1
On the Promethean Code mission, get into the second area within Rasputin. The Ghost will be on a light. Grab it by jumping on the glass window.
Bunker War 2
To get this ghost, continue on into the mission and you will find an electrical area. To the left will be a ghost behind a machine.
Crota's End 1
When you get to the Abyss, traverse to the sixth lamp and then look to your right for an ledge. Follow it to find the ghost.
Crota's End 2
At the end of the Abyss you will find a tunnel of light. Its on the last pillar. Make sure you don't go too far or you'll teleport into the next area.
Crota's End 3
Next ghost is in the final area of Crota's End. Go up the stairs to the entrance it will b e at the end of a cord.
King's Watch
Go to the Russian command centre and look for some windows. Jump through the middle one and then crouch to get through to the ghost.
The Black Garden 1
When you get to the main area look up and you should spot the ghost far up above you. Jump up to grab it.
The Black Garden 2
Continue onwards to reach an area that opens up and continue along the path until you see a large structure. The ghost is hidden there.
The Mine
While you're on the Ruling House mission, head down the left path and enter the mine. Follow onward down the passage and when you see a door the ghost will be within the area on some rocks.
Old Russia
While you're on the Fallen SABER Strike mission, break the grate before going down the hall to the final area and the ghost should be there.
Echo Chamber
Get to the room with pillars and jump onto the pillar that looks like it got cut in half. Go on up onto the bronze beam above and the ghost should be there.
Dead Ghosts From Updates
On 8th December, 2015. Destiny updated to 2.1.0 and added 4 new ghosts. They can be found in Summoning Pits.
April Update
In 12th April 2016 a new update added 1 new dead ghost. It can be found in level 41 of Prison of Elders. Keep dropping down until you see the ghost on a platform.
The Crucible
The Crucible update brought out 27 new dead ghosts to collect.
The Anomaly
At Control Zone A, go right and make it outside going beyond Zone B and make your way to Zone C. Before you get to Zone C look for some boxes and turn right to find a ghost hiding behind the boxes
Asylum
Make your way to C. There is a room past it and look for a grassy corner where a ghost is hiding in.
Bastion
Follow the road to C but when you see the second set of archways turn to the right and a ghost will be some where on the rocks.
Black Shield
Make your way to C until you reach a small passage in the left wall. Go into it to find a ghost.
Blind Watch
From the spawn point go to the left and then down some stairs. Look around in the sand on the left for the ghost.
The Burning Shrine
Once you spawn at the Burning Shrine turn around and head for the small stucture on the edge of the map boundary. Behind it is the ghost however grab and get back quick before you get killed.
Rise of Iron
8 new Dead Ghosts to the Plaguelands and an additional 4 Ghosts in the new Crucible maps.