Have you ever heard noises? Noises that you cannot just explain away, that, if you believe in spirits, are paranormal? The Noises can often be heard in dark rooms, when alone, and almost always in forests after dark.
Most paranormal entities are associated with being "evil." However, one many entities are regarded as being "good". The most commonly known entity is known as "The Guardians". The Guardians often protect an individual from evil paranormal entities, but they are often believed to be watching and guarding from a different plane of existence, thus no noises are able to be heard.
Hearing noises from paranormal entities generally means you are being haunted, in a fashion, by an entity (or rather, entities), called The Watchers...
The Watchers are undoubtedly a "bad" paranormal entity. However, they will not "haunt" an individual, rather "stalk" them, and can be linked directly to the cause of misfortunes that may befall an individual.
The Watchers can watch you from almost any vantage point, and, also being on a different plane of existence, can be anywhere to get the best "viewing angle". However, they can accidentally "trip" into this reality, thus the strange noises one can report hearing...
The Watchers often watch from windows, doorways, or even behind you (like one is now, in fact).
If need be, a Watcher is able to enter into a computer, and Watch from there.
They are often associated with glitches in computer games, and are most active in horror genre games. They are even believed to take on the form (and be the essential beginnings) of Minecraft's own Herobrine.
It is impossible to stop a Watcher from Watching (besides, of course, death, in which case the Watcher will move on to a new victim).
Be careful, they are watching even as you read...