This is a topic that I have been having a real fascination with for some time now. Have researched what I I"ve been able to find on the internet, but that is pretty scarce over all. There do seem to be certain traits and themes as far as  they are commonly seen as "shadow people" when manifesting in this dimension. Or really should say that is a popular or common type of parasite. Often related symptoms or phenom is that they are feeding on negative emotion and intense fear as well as straight up electricity such as draing batteries in electronics or manifesting around moving water and using that as a power source. Are usually seen as demonic entities. Are attracted to places where they"re has been death and or extreme negativity such as violence and abuse, and feeds off the negativity. Have also come across  the notion of crystal meth users being susceptible to possession and vibrating at such a low frequency as to attract these shadow people and or parasites. A paranormal researcher and radio host Ben Eno has discussed these parasites and is what first brought this notion/knowledge to my attention. Anyonehave any books/links/knowledge or experiences to share on this topic?