First I would determine if this was a hoax, if people were mistaking something for ghostly activity, or if there was another naturalistic explanation. If I decided it's genuine, I would feel concerned, curious, and pissed at the same time. Pissed because I hate ghosts. I believe they're demons, not dead people, who impersonate the dead to trick people into holding an unbiblical view of the afterlife. I don't think I would be afraid because I don't believe demons are able to hurt me (though they might be able to hurt others). I would probably go to the church for help in getting the demons exorcised.
You're probably right that they aren't freaking out over nothing. There are all sorts of things that can be genuinely mistaken for ghosts. Buildups of certain gases can lead people to hallucinate. Drugs can make people hallucinate. Not saying any of these are the case, but the possibilities are endless. I heard of a "haunting" in which a ghost in an attic would scream from time-to-time. It was in a rental home and people would keep moving out because they were all terrified of the "ghost" in the attic. But finally someone went into the attic and found the "ghost" was a whistle stuck into the wall. The wind outside would sometimes, when blowing into the whistle, make it sound like someone was screaming in the attic.