The following is a quote from The Historical Christ and the Theological Jesus, by Dale Allison. In discussing the historicity of various gospel events (here, the transfiguration), Allison draws from analogous stories in other religions. Here he recounts the experience of his personal friend:
"The foregoing testimonies intrigue me all the more because I personally know a man who claims to have seen a human being transfigured into light. This is not for me a foaftale, that is, it does not concern the proverbial friend-of-a-friend but comes to my ears from someone I know and have no reason to disbelieve (and who has refreshed my memory by kindly sharing with me his relevant journal entry).
In 1992 my friend John decided to seek initiation as a Sufi. The process involved having an audience with a Sufi master who was then making a tour of the States. The two men met in a small room for a short period of time. They sat face-to-face in lotus position. No words passed between them. But the occasion was memorable, for John relates that, after a bit, the master began to emit a light, which became brighter and brighter until it lit up the whole room, after which the luminescence gradually faded away, and the encounter was over."
– Dale Allison, The Historical Christ and the Theological Jesus
These type of "paranormal" events pop up in the mystic traditions with some regularity. In the Hindu tradition, they are called siddhis. What's interesting is that the mystics themselves don't attribute much importance to them. Often they are even seen in a negative sense, a potential distraction from the real work to be done.
I don't know what to make of stories like these, but I do find them interesting to think about. I think if I experienced something like this, I would take it as some type of confirmation that I was moving in the right direction.
"The miraculous" is not the heart of mysticism, but it seems to be at least potentially related.