Weird Action last night

My wife had gone upstairs presumably to bed. I was planning on answering a couple of e-mails. Our computer rests in a typical cabinet made for TVs or computers. It has two long doors that are normally closed to hide all the wires and gadgets. We don't close the doors because of numerous items that have found a home in front of the cabinet and the keyboard light which is located on one of the doors. The way the cabinet is made, the doors have about a one inch gap between the inside of the door and the cabinet housing. Anyway, with the door open you have a limited view of the doorway that leads from the dining room to the library. I was answering an E mail when I noticed a light colored clothing pass in front of the gap. Thinking it was my wife, I called out, "Ready for the computer, already?" I got no answer and no one entered the library. I figured my mistake and resumed typing. It happened again. I pulled the door forward, but there was no one there. I moved the door back and forth several times to see if I could regain the effect. There was nothing light colored even close by. Perplexed I ,again, resumed my typing and it occurred a third time. This time, I got up I went to the doorway, I checked all over. There was nothing about that could have looked like anyone passing in front of that doorway. I finished my letter, sent it and turned everything off. I needed to take Shadow (my dog out for her nightly constitutional anyway). If you think I was seeing her? Nope. Shadow is so Black she disappears in a dark room. So we went upstairs. I checked with my wife to see if she needed anything and she said she was fine. Shadow and I went into the master bedroom and prepared for the night. Shadow sleeps at the foot of the bed. My wife uses the bedroom called the Noah room because she has a leg problem that can have her up several times a night. Anyway we were well settled in, I was reading a book, as Shadow and I had already had her nightly romp before bed. I hadn't even gotten drowsy yet when I distinctly heard my name called, quite clearly and with some volume. Thinking my wife needed something I made my way to the Noah room which is immediately down the hall. When I entered the bedroom my wife was reading the newspaper and looked up with a look of surprise. "You called." I said. "No I didn't." she replied. 'Somebody did, I said, "Loud and clear". "It wasn't me" she replied. By the way, she continued, "Why are you and Shadow running up and down the hall?" "We.ve been in the bedroom for almost an hour", I replied. "Well something has been activating the hallway motion lights". It wasn't us. My wife can see the motion light from the Noah room because that bedroom has a transom over the door. When I went back to the master bedroom, I sat on the foot of the bed and petted Shadow, so I could see if the hall light would come on. It didn't. Old houses are interesting and colorful; but they can drive you nuts.