It's like just because someone is dead and is hanging around that they're suddenly hoping to kill the new occupants of their old house.
Whatever.
I thought it was the boredom that turned them mad traped between two worlds not really existing and screwing with the living is their only entertainment.
That's not always true. There are a few cases of ghosts who are trying to warn someone or make an emotional connection with the living.
For example, there's the recent one where a woman is being haunted by a widower, only to find out he's trying to warn her about having the same cancer that killed his wife. This saves her life.
There is also the case of the woman who inherits a house from her troubled mother, whom she barely knew. It turns out her mother committed suicide in the house and is trapped there. During an exorcism, they have a moment together and the mother is able to move on.
There's also a really creepy one set in a sorority, where the ghost of a pledge, who died during a botched hazing that was covered up, keeps trying to warn new pledges about the duplicitous older sorority sisters.
Yes, the ghosts are usually malevolent, or even not human, but that's not always the case.
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