First lets start off with the different types of shadow figures there are:
Shadow Beings/People are quite popular and its very common for folks to see them lurking around the place.They have no specific time to reveal themselves and come out during the night or day.
They are usually darker than the shadows around the room.
They can have a humanoid shape or just be seen as a long shadow.
Once spotted they move quickly and disappear back into the shadows.
Types of Shadow Beings/People:
Humanoid shadow being/person- has a humanoid figure.Just like a person's shadow on a sunny day.Cannot tell whether male or female does not have any facial features.
Black mist or Shadow- These are seen as dark mists that take on a human like form.Witnesses feel a sense of dread when in the presence of these.
Hat Man- Same description as the Humanoid shadow figure just with a hat.Witnesses report that there is a feeling of dread and paralysis when they see it.
Shadow animals- These are small shadows that take on the resemblance of a small guinea pig or rabbit.
Peeking Shadow People- Child size shadow figure that peeks around corners and vanishes when seen.
Red Eyed Shadow People- These have a humanoid shape and have red eyes that strikes terror and paralyzes anyone who sees them.
Now lets move on to how witnesses report when seeing these beings.Some people just get a gist that something is watching them if it is the humanoid or animal shadow being then the person just gets a feel of eyes being on them and an air of curiosity towards the shadow figure.
When it is the mist shadow figure/hat man then the person who has seen it usually reports that they felt anxious before the sighting and had a feeling of dread upon seeing it.
Now before the red eyed shadow person is seen there is a dreadful feeling in the air the person gets fearful,there chests become tight and there breathing increases upon seeing the red eyed shadow being the person gets a feeling of terror and is paralyzed with fear.
Now many people have seen these beings and no one has a definite answer as to what they are and there intended purpose.There characteristics varies like people in the world.That being said people can still be placed into categories.
Shadow beings are generally curious beings.They lurk in the shadows and observe us for whatever reasons.Some of them once you see them just go there own ways and disappear into the shadows while others don't take to well to being spotted and (my opinion) there emotions are made clear by the fear/terror that you feel.
Some say that these beings are shades,lowest forms of spirits,demons.No one associates a shadow sighting to being positive.One Pastor even said that they are energy trying to manifest itself this energy then draws energy from the living beings around it.
Psychologist say that seeing shadow people can just be a figment of the imagination.A trick of light or lack of sleep.That is there reasoning for the day sightings.For the night time they say its insufficient amount of light,when the person enters REM sleep(person is in between lala land and the real world).
It is proen that we as human beings can look at anything and find a face.So maybe its a trick ofthe mind and the feeling of fear is just your body reacting to seeing something unkown to you.
Now I don't believe it a trick of the light or your brain having a malfunction like a computer.I think they are strange dark figures that lurk in the shadows observing us.
Some links on sightings and other information that was excluded since nothing is concrete on them: