If you’re describing intermittent touch on one side of the screen, then it is likely due to a bad digitizer. You will need to get the glass digitizer replaced. An easy test is to touch and hold an icon until it shakes, then drag it all over the screen, starting on one side and dragging it the full length up and down from one side to the other. If the icon falls away from your finger, that is the section of the screen that is faulty. Very easy repair and around $100, depending on the model of iPad.