I went to a "clairvoyant evening" with a group of friends. Ever the sceptic I gave the clairvoyant a bit of a hard time.
Then she said to me that I had a room at the top of my stairs which was never used (I did, the master bathroom, I lived alone and always used the ensuite) and that this was inhabited by the ghost of a 9 year old boy. I told her the house was only 8 years old and it had been a field beforehand. No matter said she. In fairness, there were odd things that happened, but I had always put them down to my own scattiness and stupidity (like finding my fags in the fridge and my door keys in the dishwasher!), but the cat walking across the room and freezing with hair on end was a bit spooky.
So that night I had to return to a dark empty house alone, with the idea sown in my my mind that I was harbouring a fugitive. So i decided me and "Billy" as I lovingly called him from thereon in, would have a chat.
So to an empty room I explained that this was my house, and he was to live by my rules, he wasn't to mess with my stuff and he wasn't to scare the cat and as long as he behaved I wouldn't get the priest in.
I will never know to this day whether I was "haunted" or not. But everytime anything weird happened I would say "OK Billy, behave". Apart from slightly odd things happening (and I am a totally scatty cow) there was nothing massively weird and cats can be funny. Still it was vaguely amusing.
My last house however, (a 15 century farmhouse) was an entirely different prospect. There was a ghost thereof that I am sure - I never saw her, but my sister did. But I felt her presence regularly and I always knew that she was OK - there was nothing malevolent about her, just something very very sad.