I don't want you to believe anything. I am simply presenting possibilities that you seam to have completely discounted in favor of something far less likely. I don't know who would have been playing a joke, but the land lord could have been conning you. You just admitted your sister lost a months rent. Sounds like the landlord is making money on these ghosts. Are you saying that a supernatural ghost is the only answer? Its way more likely that ghost exist than a greedy land lord doing some despicable things.
Likewise just because you believe in something doesn't make it real. You can believe what you like but you have not presented any evidence that would make me believe.
I am not sure where you get that I watch too much TV but I am trying to analyze the facts. You have presented none that lead me to believe you experienced a ghost. I know enough about the particular subject to judge. If I have read a considerable amount about how ghosts don't show up under testable conditions and how a healthy human mind can come to the conclusion ghosts exist despite the lack of real evidence.