I really have no way of knowing for sure but I don't think is a ghost(spirit of a deceased person) or the product of some secret tech and/or aliens. I've done some independent reading of accounts of those under the effects of
DMT who report contacting and interacting with all manner of non-human intelligences and of indigenous interpretations of such things as contact with beings in the "spirit world".
Like I
mentioned to
Sceptic Tank I think it may be useful to think of the ostensibly 'physical' world we interact in our waking lives as a constrained subset of a much larger reality. 'Incarnated' being like us could be compared to users tunned into this particular reality frame and these "spirits" would just be beings who are not currently 'logged onto this server', so to speak
Like I said, the "voice" specifically advised me against mentioning the encounter. Whether it was because she knew reporting such things would possibly get me labeled as mentally ill or there is some larger reason why such beings do not wish to be generally known, I can't say for certain. From accounts I've read of people who 'explore' the larger reality
[via OBEs,
ayahuasca, or some other modality
] many of the entities they talk to tend to try and change the subject whenever the topic of their ontological status comes up.
I don't have enough personal experience to give any definitive answers myself. The best I can do is learn as much as I can from similar reported experiences and try to form my own conclusions about it. Whatever is going on here, I don't think it necessarily invalidates our current body of scientific knowledge; it simply means that our current models of reality are woefully incomplete.