I have had this happen before. Sometimes when you make a call and hang up before the phones connect, it can stay in the memory and call it later. It is not unheard of.

Hi, 3 days ago, i received a call for my husband cell (from samsung)a 3 am. I was surprised that the phone was charging in another room and my husband was sleeping next to me . 5 minute later the phone called me again( to Nokia). this time i was realy scared. how come a phone can call another phone by itself? i shut the 2 off an went back to sleep.
is it just a phone problem or something else? what to do? should i call t-mobile ?