Mediums are one of the best ways to communicate with spirits
The act of requesting and establishing contact between familiar spirits or the spirits of the dead and living is known as mediumship. The term ‘medium’ or ‘spirit medium’ or ‘median’ is used to describe practitioners that help people facilitate this cross-border communication.
This Redditor tried establishing a connection with the dead, and he got the soul of his deceased grandfather, unaware of him at the time. That same night, his dad came to his room to tell him how he dreamt of his grandfather talking behind him (the son). This revelation from his father shows he had already established a spiritual connection and all he had to do was listen.