Electronic voice phenomena (EVP) refers to the sounds and even voices of paranormal origin, on electronic media such as radios, tape recorders, video/audio equipment and even televisions. Some people build their own "ghost box", using a detuned AM/FM radio and speakers, so they can converse "real time" with the spirits who respond.
Proponents of EVP commonly attribute the phenomenon to communication from spirits of the dead, although others suggest it could possibly be alien communications, or even psychokinesis from the living.
I suggest that you should not attempt to conduct EVP sessions without proper taining and support. Never try this in your own home, as it is a possiblity that you might open a door to the other side, that you cannot close.
Below are videos purported to be EVPs, which were conducted and captured by means of a Ouija board and a ghost box, both of which are tools that I suggest not be used frivolously.
E.V.P. - VOICES OF THE DEAD
EVP SCARY GHOST BOY (ULTRA CLEAR)