This should be enough information to find the spirit.
If you look at the map you should find something familiar.
Location (partial solution)
The full name of the location mentioned in the morse code message is Joanna's Trail. Find the Mutilated corpse on the trail or path. It is found just outside the southeast corner of the Franklin premises. 919.7 183.0 y 158.3 3050
Although, finding the Orochi corpse isn't immediately enough to find the spirit.
You need to do something unwanted to see the spirit.
To find and to see the spirit and get the update you need to be in spirit-form yourself. This means you need to die in one way or another. Typing /reset will do a suicide on yourself.
Examine the corpse.
Find the spirit's hiding place.
Follow the spirit to the crypt inside the Mansion yards.
Banish the angry spirit.
If you click on any of the Spectral Sirens you will hear a note or tone played.
If you click on the Angry Spirit you will hear four notes played.
These are the four notes that the Angry Spirit enjoys.
To banish the spirit you can, in a way, say that you need to make it even more annoyed or angry.
Reverse the order of the four notes the Angry Spirit hums or plays.