It may be something as obvious as the base of the hands bumping against the touch pad. This used to happen to me, and it took me a while to figure out why! When the touch pad is activated this is something that can easily happen especially while typing. If, in fact, this is a lap top with a touch pad we're taking about, make sure it is de-activated.
Hello StillLearning. Bumping on the touch pad can happen just as easily if one's lap top has Windows 8.1 as it can if they're using Windows 7 (YES) ..I know..!! Go to the very bottom of your keyboard where you'll see the "FN" key below the left shift & Z keys. Hold the "FN" key while simultaneously pressing the one (F1 through F12) key at the top which displays the corresponding symbol for your touch pad. For our Sony it's F1 while on our Acer it is F7, and the symbols are as obvious as they are different! Whichever yours is, I'm sure you will find it easily!