godnotgod
Thou art That
So...the "ghost" was intractable...meaning you could suppose its existence, but in no way demonstrate it.
But you might directly experience it beyond the shadow of any doubt, as when the Buddha realized his own Supreme Enlightenment. Once experienced, there is no impetus to demonstrate it, because part of the experience is that everyone is already enlightened, though they haven't realized it yet. But you can point to the moon, which the Buddha did, though reluctantly. He left a legacy of incredible teachings of unmistakable worth and authenticity.
Personally, I don't give credence to an individual soul, or self, but to soul itself, or Universal Self. But to get to this, the personal self of Identification must first be subdued to get it's machinations out of the way.