Christmas Tree trimming ghost?

     Again, this happened to my wife and dogs. In preparation of Christmas, I have the job of setting up and decorating our Christmas tree. The tree, an artifical 12 footer, comes in four sections. Because of its size it takes a good bit of effort to even set it up. As my wife was home, I closed the parlour door because I didn't want the Schnauzers to be rough housing in that room while I was up on the ladder. The ladder is a ten foot aluminum step ladder. I had finally got the sections of the tree put together and was stringing on the electric candles toward the top. Naturely some of the candles didn't light. Remembering I had purchased some new ones a few weeks ago, I left the area and went to the attic to locate them. I could hear my two dogs having a fit ,as only spoiled dogs can do, just as I was entering the doorway leading to the attic and figured someone had come to the front door. I went on about my business getting the candle lights and a couple of extension cords. Not finding the extension cords I wanted (I needed short 6 ft ones) I came back downstairs by the rear staircase and entered the kitchen hoping to find the cords in a built-in closet. My wife said, "Where have you been?" I said,"Up in the attic getting the new lights." She said, "We've been visited again". "Oh, how so?""Didn't you hear the dogs throwing a fit?" she replied. "Yes, I admitted, "But I figured you'd answer the door". "There wasn't anyone at the door", she continued, "I came into the diningroom to see what they were carring on about and I distinctly heard you going either up the ladder or down it." "I opened the door and said,"See, its just your......", there was no one to be seen. I called, you didn't answer." I didn't hear her call, in this house, if you are only upstairs you can hardly be heard, in the attic, forget it. The dogs are schrill and their barking does carry better than a human voice. I have no idea what she thought she heard on the ladder. It wasn't me. I had been off the ladder for some time trying to figure which bulb was out on a set of candlelights, before I thought of the new ones.