I don’t have a formed a strong opinion on the matter but the Church has voiced no teaching on the existence of “ghosts” or “spirits” that are other then demonic.
We do not know what all of these manifestations are. I do know that some exorcists do believe that not all supernatural phenomena are do to demons.
To quote Thomas Aquinas:
Article 3. Whether the souls who are in heaven or hell are able to go from thence?
(objections…)
I answer that, There are two ways of understanding a person to leave hell or heaven. First, that he goes from thence simply, so that heaven or hell be no longer his place: and in this way no one who is finally consigned to hell or heaven can go from thence, as we shall state further on (71, 5, ad 5). Secondly, they may be understood to go forth for a time: and here we must distinguish what befits them according to the order of nature, and what according to the order of Divine providence; for as Augustine says (De Cura pro Mort. xvi): “Human affairs have their limits other than have the wonders of the Divine power,nature’s works differ from those which are done miraculously.” Consequently, according to the natural course, the separated souls consigned to their respective abodes are utterly cut off from communication with the living. For according to the course of nature men living in mortal bodies are not immediately united to separate substances, since their entire knowledge arises from the senses: nor would it be fitting for them to leave their abode for any purpose other than to take part in the affairs of the living.
Nevertheless, according to the disposition of Divine providence separated souls sometimes come forth from their abode and appear to men, as Augustine, in the book quoted above, relates of the martyr Felixwho appeared visibly to the people of Nola when they were besieged by the barbarians.** It is also credible that this may occur sometimes to the damned, and that for man’s instruction and intimidation they be permitted to appear to the living; or again in order to seek our suffrages, as to those who are detained (name removed by moderator)urgatory, as evidenced by many instances related in the fourth book of the Dialogues.** There is, however, this difference between the saints and the damned, that the saints can appear when they will to the living, but not the damned; for even as the saints while living in the flesh are able by the gifts of gratuitous grace to heal and work wonders, which can only be done miraculously by the Divine power, and cannot be done by those who lack this gift, so it is not unfitting for the souls of the saints to be endowed with a power in virtue of their glory,** so that they are able to appear wondrously to the living, when they will: while others are unable to do so unless they be sometimes permitted.
**
Reply to Objection 6. Although the souls of the saints or of the damned are sometimes actually present where they appear, we are not to believe that this is always so:
for sometimes these apparitions occur topersons whether asleep or awake by the activity of good or wicked angels in order to instruct or deceivethe living. Thus sometimes even the living appear to others and tell them many things in their sleep; and yet it is clear that they are not present, as Augustine proves from many instances (De Cura pro Mort. xi, xii).
and as well a post from another forum:
Catechism of the Catholic Church
1021 Death puts an end to human life as the time open to either accepting or rejecting the divine grace manifested in Christ. The New Testament speaks of judgment primarily in its aspect of the final encounter with Christ in his second coming, but also repeatedly affirms that each will be rewarded immediately after death in accordance with his works and faith. the parable of the poor man Lazarus and the words of Christ on the cross to the good thief, as well as other New Testament texts speak of a final destiny of the soul -a destiny which can be different for some and for others.
1022 Each man receives his eternal retribution in his immortal soul at the very moment of his death, in a particular judgment that refers his life to Christ: either entrance into the blessedness of heaven-through a purification or immediately,-or immediate and everlasting damnation.
So we can conclude from these that if we living beings find ourselves interacting with a deceased human entity, this entity has already faced its judgement. Therefore it may be a damned soul, in which case it may seek to cause us grave harm, or it may be a saved soul. Of the souls of the saved, it may be undergoing purgation, in which case it is in need of our prayers, or it may be a member of the Church Triumphant, and therefore be able to intercede for us with the power of the saints.
Source for this reply:
phatmass.com/phorum/topic/123263-ghosts-and-poltergeists-herbert-thurston-sj/
What I am basically saying is that there are no “ghosts” per say stuck in no-mans land, but merely either damned souls, demons, or saints/those of heaven. As to communication with such spirits obviously the invocation of the help of the saints is only advised.