Yes, when I was around 20 or so I had a Profound Religious Experience. I had it while meditating. At the time I was meditating regularly every day, just settling my thoughts down and counting my breaths. It was very relaxing. A book about meditation that I owned offered a meditative exercise. I was to move from a meditative space right into talking to myself in my head. The book assured me that eventually I would start answering myself and that other voices would join in and I would be able to have a lively conversation with myself. Well, that did happen. There were at least three or four of us in there and then this demonically deep voice began growling at me in a language I couldn't understand! I was frightened and intrigued. I wanted to know what it had to say and who it was. I asked it to make itself understood and it only responded with the same arcane grunts and growls but it showed me images! Pictures entered my head! Fire. A volcano. Deep within the volcano, an embryo. I felt that the embryo was me and that I was safe in the volcano's womb.
I came out of it quickly, but couldn't stop thinking about it. What could it mean? Who was the voice? I had discovered something profound and spiritually significant and I couldn't wait to tell my friends about it. When I met up with my friends later I told one of them, a lady that I had a lot of respect for, and she shut me down in a way that I'm completely grateful for now. She suggested that my subconscious was giving me something to obsess over, something to hold my interest. There was no demon, or deep one, or elder god giving me secret messages, just my own brain trying to liven things up a bit.
That makes so much more sense than something otherworldly. No one has ever reliably seen a demon, or a god, or an angel, or any other such thing, but we have seen brains. Lots of them, and we know the power they have to generate woo.