I often experienced his doppelganger.
Grave.Disorder, my opinion is that it is not a residual haunt, but a very specific one, which has one specific objective, that being to replace the person being haunted."Residual energy" almost always sticks pretty much to a specific area. There are many reasons for residual energy, but for me, the outcome is the creation of either positive or negative energy. An example of this is where a house may have had one owner and that owner (family) were pretty much a happy family and then the house goes up for sale. When I have gone through the house I can pick up on the positive energy, which is a wonderful feeling.There are times where the opposite occurs and it is not very good and in my case can be so bad as to create a feeling of nausea. Not a good feeling at all.Residual energy can stay in a specific spot for hundreds / thousands of years.