Do you have an opinion..let's here it!
It is forbidden by the Catholic faith to have anything to do with that. It is a grievious sin against the first two commandments.
I am the Lord thy God:
1. Thou shalt not have strange gods before Me;
2. Thou shalt not take the Name of the Lord thy God in vain;
It is the sin of superstitution to have anything to do with what are communications with the Devil and the demons. In the Eastern Church there is version of this which known as toll houses and is totally demonic and evil.
I think you misunderstood the question.
The poster was asking about GHOSTS, not SPIRITISM or PSYCHICS.
Ghosts are souls of dead human beings who are given permission to manifest themselves in some way -- perhaps because a great injustice was done to them. For example, a man leaves $20,000 in his will to have Masses said for his soul, but his son decides a new boat would be a better way to spend the money. The poor deceased father will now have to spend longer in Purgatory because of an injustice done by the son. I could easily see God allowing the father to appear to his materialistic son to scare him/get him to undo the injustice.
Anyhow, when a ghost visits you, you have no say in the matter.
But getting involved in the occult, magic, communicating with the dead (nevermind devils) is just as you say -- a sin.
The Catholic position is, "of course Ghosts exist. Human beings have souls that survive the body's death. And there is a place called Purgatory."
Read the book "Purgatory explained" for plenty of true "ghost stories".