Ignition Switch problems of the 1999 GMC Sierra 1500

While driving on a street in my neighborhood, we found that the ignition switch could be moved to the "off" or "accessory" position while driving. Noticed that steering, brakes, and other components became disabled. Luckily we were able to safely move the vehicle to the roadside and assess the situation. A problem like this could result in catastrophic system failure in the vehicle while driving at high speeds, and could cause possible death if we weren't aware of this problem. Please inform other vehicle owners of this possible dangerous issue.