Screen spazzes out when not touching

My wife got my tablet yesterday for Christmas. Yesterday it worked perfect. Today though the screen started to spaz out on me. It will move up and down, zoom in & out, move side to side, randomly click on things. The problem is that I am not touching the screen. It will stop once I lock the tablet. I will clean the screen and it will be fine for about 30 minutes. Any thoughts as to what to do?