Ectoplasm

Ectoplasm is said to be produced by physical mediums when in a trance state. This material is excreted as a gauze-like substance from orifices on the medium's body and spiritual entities are said to drape this substance over their nonphysical body, enabling them to interact in our physical universe.
Although the term is widespread in popular culture, the physical existence of ectoplasm is not accepted by science. Some tested samples purported to be ectoplasm have been found to be various non-paranormal substances. Other researchers have duplicated, with non-supernatural materials, the photographic effects sometimes said to prove the existence of ectoplasm.

 Who can forget the all famous scene in Haunting From Connecticut, featuring the young man with ectoplasm pouring out of him ?

 Ectoplasm dose not just come out of mediums it can be caught on film anywhere.

I myself do not believe that this substance comes from people and if something is caught on film like this it is not of a solid form it would have to be a spirit trying to manifest. I have no clue but anyone can put pillow stuffing in their mouth, take a picture, and call ectoplasm.

 It was said when people held seances someone would make a connection with the dead and ectoplasm would escape their body. 

                                 I think this woman has a sheer curtain or cloth in her mouth, you can see the hemmed sewing line on the sheer fabric.

                                                       This is so fake and very funny

        Maybe a big doily bunched and rolled up to get this effect, I can see the laced pattern.

  If your going to fake it at least make it half way believable.