No but I have heard of the scientific theory regarding our mantel. Inner core, and outter core not being one solid mass. However I am still of a mind that the idea of beings living in this pockets of space just doesnt really resonate with me. I have a difficult time believing these pockets are permenant for one as in my mind they are not structurally sound I see them more as large gaseous bubbles that form and dissipate more or less. This is my issue with the theory. I know things can live basically anywhere in the universe and I do not believe liquid water is necessary for life it is mainly the structural composition and if they are stable.
Remember: This life is only temporary so make the most of it