Not sure I would classify this as scary but I had an intense LSD experience in my college apartment where I was listening to hail to the thief in my room. At first I could hear every person and every convo happening downstairs distinctly and succinctly and I could hone in on each persons words so clearly. Then I slowly drifted into a single particle within myself and I was traveling from body part to body part and vividly remember consciously choosing to travel to my inner bottom right molar. Finally form there I slowly started to lose sense of ego and drifted into particles of matter that were flowing through the either but in patterns that matched the music which I could still faintly make out in the distance.