No, they are demons masquerading as spirits of the dead. These demonic spirits are familiar with the deceased individual whom they wish to imitate. It would appear this is why they are able to supply people with accurate details of names, places, and facts.Their purpose to deceive those they "haunt" and to turn our attention to them, instead of God. That is why many will appear to be friendly. It would encourage you to commune with them. They may even perform minor wonders that would impress you. But be not deceived! The Bible warns us that our struggle is not against flesh and blood, but against powers of this world and against the spiritual forces of evil. (Ephesians 6:12) These spirits serve one master. His name is Satan.
Here is a scenario. You die. Your spirit (or whatever you want to call it) for some reason decides to hang around. Here are your options. You can go to someone's house and scare the crap out of an innocent family or you can go to a scientist and try to figure out what is happening to you. Why is it that every single ghost has chosen to scare the crap out of someone? Why hasn't ONE ghost ever decided to submit themselves to a scientific investigation? It doesn't make sense! Oh wait...what if there are no ghosts...well now it makes sense!
Given our society's current interest in "supernatural" phenomena, this is an important question. Some people reject the idea of ghosts as crazy or superstitious, putting them on the same level as werewolves, vampires, or extraterrestrials. But let's take a look at what Catholic teaching has to say on the matter. Before we can ask whether ghosts exist, we need to be clear on what we're talking about. A "ghost," according to the definition found in Webster's New Collegiate dictionary, is a "the soul of a dead person, a disembodied human spirit." So a ghost is NOT an angel or a demon; rather, it is that part of a human being. - the soul or spirit - which is separated from the body at death. So everyone now in heaven, hell, or purgatory could be called a "ghost," and this will be the case until the Last Judgment, when our souls will be reunited with our bodies. In this sense, we as Catholics affirm that "ghosts" exist. (My answer continues in the comments)
Yes they do. Believe in them or not, they are out there. Ghost are the spirits of humans/animals that got left behind. Some ghost are human-like that they could be classified as demons, such as poltergeists.
1 John 5:19. "We know that we are children of God and that all the rest of around us is under SATAN'S power and control."( Living Bible) people say there is no satan and their is no God. Even in Bible times. And today people say there is no satan.! "That Man is a fool who says to himself "There is no God!" Anyone who talks like that is warped and evil and cannot really be a good person at all." Psalms 14:1 (Living Bible) Bible says that there is evil and there is good.