The dell laptop I got off ebay was giving me fits. I would be typing and then words would appear at top of text or who knows where. The cursor was jumping all over the place. Well I figured out my thumps were bumping the mouse keys just below the space bar. This computer has 2 sets of mouse keys, so I don't know why there is a set below the space bar. I took a pop cycle stick and taped the the stick over the 2 keys below the space bar, problem solved.
I used scotch tape, I'm sure Bubba would have used duct tape.