Actually, psychics are not professionals as their gifts vary in degree. For example, I am clairsentient and often pick up vibrations in your thought patterns. Some are clairaudient and others clairvoyant. Still, others are psychic mediums. Please respect our gifts and do not generalize, lumping everyone into one trash bin. Psychic phenomena is by no means an exacting field. It is often subjective and sometimes manifests; so that others may receive "proof" with cameras and other types of equipment designed to pick up high frequency vibrations.
If you wish to familiarize yourself with how they work, please be specific in your questions because your doubt is reading loud and clear.