Has Listening Again Reopened a Door?

I have been ignoring the "spirit world" for many years because it scared me. But, of course there are those times when they force their presence on me. Lately I have been interested again. Mainly because I can talk about things (via web) without anyone knowing who I am.

Anyway, since I have been paying attention to things that have been happening. Perfect example is yesterday. I work in a school teaching preschoolers science. The school is an old two story house that has been around since the 1800s. There has never been any and I mean any disturbances. Yesterday as I was teaching the after school students, downstairs in a back room, I heard something up above us running around. I thought that one of the teachers was upstairs. It never crossed my mind that it was anything other than a living person. When my last student left I went into the kitchen area and helped another teacher clean up. We heard someone walking upstairs. I asked who it was and she told me that another teacher was upstairs. About ten minutes later we were done and gathered our things and headed out the door which was just behind us (the only door that we used). We heard the walking around again. The teacher with me yelled up to the other teacher informing her that we were leaving and we would see her tomorrow. We waited for a response but heard nothing. The teacher with me set her things down and went upstairs. She came down and said no one was upstairs. We left the building very fast.

Could I have possibly opened up something by trying to see again?