Ghosts are real. The most important thing to know is that ghosts are just human beings not living in physical bodies. There are lots of reasons why a ghost's attention may be focused at the level of physical world reality, but that focus of attention is what brings them to your awareness and keeps them there.
Paranormal activity is from demons as the person before me stated. They are cunning and tricky. They can imitate dead people which is why people think they are dead people. to call on the name of the lord is simply not enough. the re is an account in the bible that clearly shows that. A man was approached by demons and said something to that effect. what did they say to him? WE KNOW who he is but who are you!!! However the name of GOD which is Jehovah is a strong tower and when the demons hear his name they shudder. But one must try to come to an accurate understanding of how that works. Here is a partial copy with scriptural reference Below.