This is a fascinating paper that suggests weak magnetic fields induce mystical experience remarkably similar to those induced by DMT.

Hill, D., & Persinger, M. (2003). Application of transcerebral, weak (1 microT) complex magnetic fields and mystical experiences: are they generated by field-induced dimethyltryptamine release from the pineal organ?. Perceptual And Motor Skills, 97(3 Pt 2), 1049-1050.

Following up on this, here are the papers cited.

Persinger, M. (1988 ). Increased geomagnetic activity and the occurrence of bereavement hallucinations: evidence for melatonin-mediated microseizuring in the temporal lobe. Neuroscience Letters, 88(3), 271-274.

Persinger, M., & Richards, P. (1995). Vestibular experiences of humans during brief periods of partial sensory deprivation are enhanced when daily geomagnetic activity exceeds 15-20 nT. Neuroscience Letters, 194(1-2), 69-72.

Persinger, M. A. (1999). Near-death experiences and ecstasy: A product of the organization of the human brain. In S. Sala (Ed.) , Mind myths: Exploring popular assumptions about the mind and brain (pp. 85-99). New York, NY US: John Wiley & Sons Ltd.

PERSINGERM, . A. (2000) The UFO experience: a normal correlate of human brain function. In D. M. Jacobs (Ed.), UFOs and abductions: challenging the borders of knowledge. Lawrence, KS: Univer. of Kansas. Pp. 262-302.