Haven't read through the whole article yet, but I like what the author is saying. From what I have read, I see ghosts in a similar manner; they may not be actual spirits running around "living" it up, but they aren't quite metaphors related to our ideas and feelings around death either, but somehow in between.
I use the analogy "the map is not the territory" quite a bit, and it's particularly useful here. The map is the symbol, the territory is the reality, and one could say that the traveler experiences the inbetween state (the numinous) from the time of imagining, preparing for, and taking the journey. The map is a symbol for the reality of the landscape that can be tested, photographed, experienced, but the traveler experiences something in between these that could never again be "real," wrapped up in various mental and emotional connections, associations, and individual nuances that make the journey a ghost to be consigned to the brain of the individual that can never quite describe or explain it.
Similarly, after my grandmother died, my family was cleaning the house out, doing all those emotional things people do for necessity and to let go. I was the last one to leave (the last time I was to be in the house) when I heard clear, unmistakable footsteps in the attic. It could have been any sort of mundane, realistic thing, but in that moment of severe vulnerability and emotional needs, it hit me in that unreal reality that the author desribes as "That warped smile and those red eyes might not be staring back at me from the yard, but they’re staring back from somewhere."
Not quite a metaphor and not quite a real spirit (as far as science can verify), but something wrapped in all the individual nuances of my own sublime reality.