Bill Wilson, the cofounder of Alcoholics Anonymous (AA), had a spiritual awakening that involved bright light, sometimes referred to as his “hot flash” or “white light transformation.”
Mysticism seems to be largely misunderstood. It seems to be either thought of as a kind of ethereal and vague mystery that can never be really known, or as an impractical lofty exercise that can never truly be achieved, at least in this life. For me, it is neither.
There is an experience which grows in the soul out of the soul itself, without contact and without restraint, in naked oneness. It comes into being and completes itself beyond the commotion, free of the other, inaccessible to the other. It needs no nourishment, and no poison can touch it. The soul which stands in it stands in itself, has itself, experiences itself - boundlessly.
For it is a property of the Good that it becomes known to him who is able to see it... It shines forth much or little, according as he who gazes on it is able to receive the inflow of the incorporeal radiance... It is full of immortal life.
Meditation begins as most do. I feel as if I am a small stone sinking into an ocean of filtered light. The light seems to be coming from all directions. I slow, almost pause, at certain levels before my specific gravity increases again, and I sink deeper into this ocean of consciousness—no real experience of having entered this ocean—just being there and going deeper and deeper. It is beyond peaceful, beyond serene.
This is an account written by Norris Stearns of Greenfield, Massachusetts, published in 1815, five years before Joseph Smith's First Vision experience, in a pamphlet titled The Religious Experience Of Norris Stearns Written by Divine Command. The 35 page pamphlet can be read in its entirety online at this link. Here is an excerpt of part of his vision.