IF, and that’s a big if, the story is true. Where did they Non-Humans come from? 1. Other planets? Hard to believe. No Martians. 2. Other dementions of reality? Possible. 3. The Future—Time machines looking back at us? 4. The past advanced cultures from before the flood? 5. The bottom of the sea? 6. The Inner Earth? 7. The hollow Moon? 8. Antarctica? 9 Take your pick.
“Where did they Non-Humans come from?”
This essay discusses your questions in great depth:
https://thejournalofcosmology.com/Puthoff.pdf