When I was younger, I lived in another country. I moved to the United States to live with my dad when I was five. My sister and I were instantly pulled into the world of the supernatural and certainly were what you would call obsessed. When I look back on it now I can trace our obsession to the constant drool of ghost stories coming out of my uncle's mouth at that time. Our grandpa was also very intent on scaring us to death. Naturally we honored what they told us.
After a while we tired of ghost stories and convinced ourselves that there was a presence in our rented apartment. Of course there was nothing there... At the time. We grew obsessed with trying to talk this "spirit" and tried all forms of communication with this thing. We set up sticky notes with questions about the ghost. We even attempted a seance at one time or another. We used our mom's tape recorder to try and capture any sounds in our room. Nothing came out of these tests.
After a while we got tired of ghost hunting and, as children, focused on various other things. During the last few months that I lived in the apartment (my parents bought a house and so we were moving) strange things started happening. I can't quite place what was happening but during those months I slept less, ate less and experienced nightmares like I never imagined.
My parents have attributed this to the anxiety of leaving a place you have lived in for so long, but somehow I doubt it. I felt something in that house and of course it was like nothing I had felt before. My cat acted strange also, so I know that it was something slightly more worrisome than moving anxiety.
I left something there... All my years of poking into whatever other world I believed there was. I left it in that house and maybe... Just maybe part of it followed me... This is a true story, not something I made up.
I have a few questions:
First, DID YOU USE AN OUIJA BOARD? I did hit the caps lock on purpose, because this is a key question. If you did, even though you got no results, you may have attracted something. And that is truly frightening.
Second, do you have anything in your belongings of the house that was there before you moved there except, well, pieces of the house (i.e.: Vases, dolls, paper, etc...)? That might be the cause of the strange feeling. I've heard a few stories and cases where moving something from it's original house can cause an upset since so much energy is attached to it.
Third, have you done any contact with spirits since? Such as a seance, the post-it notes, etc...
Overall, I suggest the possibility of getting a local priest or whatever religious leader that you wish to use to give the house a final blessing before you leave, or even doing so yourself.