Strange footfalls heard again.

Today, I was working in the attic, trying to make more room for more stuff we rarely use. Our attic is quite large as attics go and is divided into two rooms. The front room has 8ft ceilings in the center and slope downward on both sides to roughly 5 ft. The ceiling of this front room was, at some time in the past, finished with plaster ceiling. Over the years, primarily when this house sat empty the roof leaked and ruined much of the ceiling. The back half of the attic was never finished and stands roughly 7 ft at the center with the rafter and roofing slats quite bare. Over top of the roof slats is an old tin roof. This roof sprouts an occassional seep leak which is duly noted and stopped with tar or Elasmaric roofing compound. I had started to fiberglass between the studs; but have not progressed very fast as there is a lot of "stuff" to climb over. Today I had been working for an hour or so in the front room of the attic when I heard, no question, the attic door open (It is very close to the hallway carpet and drags slowly over it when you open or close that door. The sound is characteristic and like nothing else. I then heard heavy footsteps accend the attic stairs. Again, no mistake, as the attic stairs are bare wood and hard soled shoes make quite a racket. My wife absolutely refuses to come up to the attic. In 30 years she may have been there very briefly twice. Even so, because there was noone else around, I assumed it must be my wife. I called out from the front room, of the attic, that I was in there. I got no response. Figuring that if it was important enough for her to come to the attic; I'd better see whats was up. But there was no one in the attic but me. I did not hear anyone decend the stairs and that would have made as much noise as coming up them. There simply was no one around who could have made those sounds. I went down to the second floor and stepped around to the back stairwell to the kitchen and shouted down to the first floor (the kitchen is just off the backstairs) asking my wife if she had been upstairs. She assured me that she had not. Later, over supper, I told her what I had heard. She replied, "You couldn't get me on those attic stairs and you know it." Chuckling, she said maybe it was Mrs. Ramsbottom. When this house was built for a U.S. Senator in 1857, he and his family had a personal black servant (paid not slave) who lived in the attic of the house with her young son. This is who my wife was referring to. The son later grew up to become a bishop in one of the larger church bodies). He did his homework on the walls of the attic which was still in evidence when I bought the place about 30 years ago.