I've experienced this as well. I have suffered with it so many times. I have heard voices, hallucinated and I have had a feeling of dread when it happens. I heard a woman call my name twice while I was experiencing sleep paralysis and that was creepy. When I'm experiencing sleep paralysis I pray in my head and one time I felt something on my bed, it felt like a dog would be lying on my bed but nothing was there. I prayed and it went away. I think these attacks happen because I sleep on my back. You shouldn't be freaked out or scared when you're experiencing sleep paralysis, just lie still or try to bite your lip or move one part of your body and think you'll be able to move in a minute. I try moving parts of my body so that it can wake me up. I understand it can be scary. I'm kind of used to it, now I feel like they're a minute long. The cause of sleep paralysis could be... that you might be over sleeping, your sleep routine might be mucked up or you sleep on your back.