invisible voice- there is someone or something in my dreams

Hello,

I have had a dream, with an invisible voice. I have not thought much about it, but after a little bit of time I have had a second dream with the same voice.

In the first dream I was in the house of my grandparents, I found a book of mathematics. I was curious and want to read it, but the book disappeared and then it was there again, but with a second yellow book, I think it was concerning magick and I heard a voice, saying: "I can teach you a lot"
In the second dream after a little bit of time, I was in the house of my parents in the room of my childhood. There was this voice again. I was sitting in my bed and I felt that I loose control of my body and I am near to leaving my body. I was half out of my body and I got fear and stopped. There was again this voice. It said: "You have to master this step first, to come closer to me"

I think that were not normal dreams. I am very perplexed. There is something or someone who wants to guide me. But I have no idea what it is, where it comes and what it wants.
And I don t know what this voice exactly is. Perhaps it is my inner guide or a ghost, or a demon, I don't know. I am unsure. What it wants from me? Just helping me, would be a very fine thing but I don't think that all spirits are gentle like this.

This voice wants that I learn astral projection. I have never touched this topic and I have a little bit fear that this spirit has not just good intentions.

Is there anyone hearing voices in dreams too? Is this possible that someone/something from the astral plane enter in my dreams? Or is there someone who have an explication for this?