Here we see a photograph of the independent direct-voice medium  Jack Webber. Clearly, a very long ectoplasmic structure can be seen oozing from his mouth.

Depending on the level of ability possessed by the medium, this ectoplasm will very often continue to develop until it becomes independent from the medium forming its own intelligence.  This intelligence, however, does not originate from the medium's mind.  It is controlled by the intelligence of etheric (deceased) individuals who use this substance to clothe their etheric bodies during materialisation experiments.  This allows them to be seen, touched and heard in our physical world by all those present.