Hello Rabbi Maroof,
Please tell me if it is a wrong thing to be a medium; if I can form a link with a soul from the next world and relay information to the sitter, is that wrong?
In the Book of Deuteronomy, we are told:
There shall not be found among you one who passes his son through the fire; a diviner, an astrologer, one who reads omens or a sorcerer. One who charms animals, one who inquires of Ov or Yideoni, or one who consults the dead. For anyone who does these is an abomination of Hashem; and, because of these abominations, Hashem, your God, banishes the nations from before you.
The Torah clearly prohibits any attempt to communicate with the dead. Maimonides explains the reason for this law:
All of these things are matters of falsehood and lies, and they are the very means through which the idol worshipers fooled the nations of the world into following them. And it is not proper for the Jewish people, who are exceptionally wise, to follow after these vanities, nor to entertain the possibility that they have any benefit...Anyone who believes in these things and things like them, and thinks in his heart that they are true and wise but that the Torah has prohibited them; he is one of the fools and those lacking knowledge... But those who possess wisdom and sound mind know by clear demonstration that all of these things that the Torah prohibits are not things of wisdom; rather, they are emptiness and vanity that fools stray after, and all of the paths of truth have been corrupted because of them. Because of this the Torah states, when it warns us about these vanities, "Perfect shall you be with Hashem, your God."
In other words, we reject these practices because they encourage magical and mystical ways of thinking that contradict the wise paths of our holy Torah. There is no rational basis for them whatsoever.
Those who seek mediums are usually emotionally troubled individuals who have unresolved issues with loved ones who are deceased. Instead of attempting to gain insight into their internal conflicts and resolve them, these people turn to charlatans who offer to help them "reconnect" with their dead relatives - for a price, of course.
The best thing you can do is suggest that these unfortunate human beings seek professional help to deal with their emotional difficulties. This is the healthy, reasonable approach that is advocated by our Torah. Perhaps then they will no longer feel a need to chase after fantasy and will begin to appreciate the value of wisdom.