The imagination is a wonderful, powerful thing.
I'm not saying that all disembodied visitors are imaginary, but often when people feel kriyas occurring at night or during meditation, they mistake the spontaneous sensations and muscle movements as some outside force at work on them, and imagination fills in the details. they may get very upset, frightened and frustrated when they discover that no amount of prayer or exorcism will banish the visitors they imagine!
So, when experiencing visitations, the first thing to ask yourself, is whether the sensations you feel, really are coming from outside of yourself.
The next thing to ask yourself, if the answer is 'yes' is whether the sensations are caused by your Divine Beloved interacting with you. This is a positive thing, and there is nothing you need to do about it, although you can request that the visitations come in a less unsettling form. Your Divine Beloved is a part of you, your infinitely wise and loving unconscious mind.
Poltergeist phenomena are most often caused by someone who has telekinetic ability and does not know it. They experience things moving of their own accord, and assume some demonic force is at work, when it is simply their own power manifesting unconsciously. The simplest thing is to ask for the power to be taken away temporarily, and returned at a later time when the subject is more prepared to use it wisely.
Faeries, sometimes called Devas or nature spirits, have the power to make objects move, disappear and reappear somewhere else. Most faeries have little interest in the activities of humans, but some are benevolent and can be good teachers. Occasionally one will encounter an angry or malicious faerie. This is usually a reaction to human interference. If you were a naiad and someone turned your stream into a sewer pipe, you would be pissed off, too! Some types of magical workers will enslave nature spirits and bend them to their will, and the result is an insane Faerie who will long outlive the misguided magician who warped them. These are best sent into the Light for spiritual rehabilitation. Essentially, their mischief is a way to get attention so you will help them, much like a misbehaving child might do.
Some disembodied visitors may be ghosts, and there are essays on this site that deal with that topic:
Types of Ghosts and Spirits.
Entities: thought forms, memes, astral junk.
The best visitors are the Ascended Masters and Archetypal Deities who may appear to assist with your progress. Their visits will usually feel benevolent, although some deities like Dark Kali may be a little scary, but will be very positive in the long term.
The best way to prevent unwanted visitations from unfriendly spirits, is to ward your space, create a magical circle or bubble spell boundary that is guarded and maintained by your higher self and guardian angels. Request that they not allow any entity or spirit contact with you, unless it is in service to the Light and to your highest good.