When you first experience something you can’t explain, your mind does what we like to call an automatic logic scan, in other words, we try to come up with a logical explanation for what it was that you just experienced. When your mind fails to find that explanation, you turn to the idea of paranormal activity. These encounters can be in any category of the paranormal, rather it is a UFO sighting or a run-in with a ghost you are most likely to experience a mild form of shock or panic.
In ufology, we categorize sightings or experiences as close encounters or CE’s, it has a scale that ranges from CE1-CE4 depending on the intensity of the experience. With ghost it's about the same, we judge the experiences on the type of encounter that it is. You hear about how people report seeing a ghost in full, like down a hallway or in a corner. Perhaps, it’s appliances turning themselves on or off. After an experience, you can’t seem to get it out of your head for a few days, you relive the encounter over and over again, still trying to find an explanation that makes sense. (At least this is how it is for some people)
No matter the experience you are dealing with, you will know right away if something weird is happening or about to happen. Ghosts and hauntings are more common than those of UFO sightings. You can live in a haunted house years before noticing anything out of place. It’s important to note that paranormal activity can occur at any time of the day, but it rises sufficiently between the hours of 12:00 AM - 6:00 AM and peaking at 3:00 AM.
As you see your first unexplained shadow or hear that first unexplained voice in your house, you may experience a mild form of shock, it’s been described more of a stunned feeling. No doubt you too will begin to question what you just experienced. Skeptics will usually work really hard to explain an encounter, even when it becomes clear that an explanation is unlikely.
Analyzing your experiences on a logical and scientific ground should be the first thing you do. However, many of those who have an encounter atomically jump to the thought that it's a ghost. Not saying anybody's experience isn't of a paranormal nature, just saying we need to at least look at other explanations for the countless things that have happened throughout history first and then move our way to the paranormal conclusion when we fail to explain it.