No amount of discussion here is going to produce a definitive answer, but if I say I've seen a ghost and you can't get your head around that, that isn't my problem. I'm not asking you to believe me, but please don't tell me I haven't seen what I know I've seen.
//......what is the manifestation composed of?//
Some form of residual energy? We just don't know, but personally rather than impede my intellect by limiting it to the barriers of current knowledge, I will continue to consider all potential possibilities. I know what I've experienced, but I don't know what it was or what caused it. If lack of experience leads you to slam the door shut then so be it, but I know there is something happening in this world for which we have no explanation and I think that warrants continued investigation.