Cruise Control

I have a "98" Aurora, The other day my wife said the Cruise control came on by it self, then yesterday she said it came on again and actually started speeding up. Has anyone else had this problem? And does anyone have any idea what to look for to fix the problem or is this a dealer fix. I turned it off so it won't come back on but if its an easy fix i would like to cure the problem. Thanks, Randy