My understanding of the rebirth process was even before Buddha Dhamma (but I was interested in vedas and upanishads) I realized rebirth process true observing natural phenomena like plants giving up seeds and from that seed new life appeared when those conditions was applicable for them which I woke up to understanding of rebirth process. We can deduce all micca ditthi by observing natural way. I had also encounters with spirits or ghost I guess so for me it was pretty natural to not having micca ditthi even before attending Pure Buddha Dhamma.
A Quest to Recover Buddha's True Teachings