Well I just signed up today

Searching the www I did not find any explanation to my question of how or why does this SP happen to me. Sure there are explanations of the SP but the type I experiance did not come up.
Usually it happens when i nap and its about ten min. into when i lay down. i hear a very loud vibrational sound fallowed be someone familiar right next to me or walking around in the same room i am at. Its not a warm feeling. And i see the whole thing even though i beleive my eyes are closed. It was today that was really weied. i'm laying there and see my little brother standing right next to me. I thougnt 'this is strange - why is he here' then it became very scary and i had to tell my mind to wake up so my body could move. Yet sometimes I can completly control what is happening in my dream/SP state. I don't know, i'm probably doing this whole thread thing wrong :-) I just am curious what is happening and how do I get beyond that scary feeling to a state of control :-)
Thankyou
havalah