What is a medium?
A Medium is a go between – someone who can traverse and communicate with other beings either in this world or the next. They may also have contact with beings not of this realm or dimension, for many can channel entities from other existances, planets, star systems, etc. But for the most part, people seek a medium to communicate with loved ones who have passed on into the realm of spirit.
No one can guarantee a contact, for the medium is only a channel for that higher or lower vibrational freqency and none can demand or directly request it. So never go with high expectations – just be open for the possible experience.