Scary noises in this old house...

I love old houses but they creep me out at the same time. I have probably just seen one too many scary movies but if I hear a sound my ears perk up. This house that we live in was probably built in the 50's but I'm not sure I just know it's fairly old. I always hear little creaks and sounds so I always sleep with a fan on and a night light. That's right a night light I'm not too scared to admit that I'm a big scaredy cat.
Our computer is in the basement of our house and thankfully I'm not real creeped out about it down here or at least I try not to be. Sitting here in the basement I hear a few different noises most of which I can name what they are but if I do hear something that seems weird I run upstairs to investigate. Tonight as I was working on a blog post I thought I could hear someone walking around upstairs. Brett was at work and the girls were both snugly in their beds. I walked upstairs to look around but nothing seemed to be amiss. I went in and checked on Madi and she was in her bed, not in a deep sleep yet but in her bed. I just told myself that it was old house noises and then the furnace had just turned off so that was probably some of the noise too. So I went back to my post then I heard noises again. It sounded like someone was walking in the living room and maybe the master bedroom. It was really starting to freak me out. I went up and looked around again but didn't see anything. A little bit later the furnace had kicked on and then off again and then I heard it.... Madi was running around upstairs. That little munchkin was getting into anything and everything. Mystery solved!! I guess getting spooked like this helps to keep my heart healthy... I am such a wimp. Ahhh!! Just as I wrote that I heard a noise from upstairs and then this loud rumble.... Darn that furnace!!!! Hopefully I'll get used to all of these noises soon and then I'll be able to tell when Madi is running amuck.