MacBook Pro trackpad goes erratic when paper touches it Whenever I set a piece of paper or a notebook with paper over my trackpad, it begins to act erratically for hours at a time. By erratic, I mean the mouse jumps around the screen and sometimes even clicks / right-clicks. This has been happening for several years (my MBP is from 2010, late-fall 15" i7). 

I've never bothered to take it in, because it usually goes away. It also helps if I vigorously wipe it with a dry cloth.

Does anyone know the cause of this? Is there some type of oil on paper that could be the culprit?
The oils in your skin and lotion can sometimes have an effect on your trackpad. The best way to clean it is with a damp, clean, lint-free cloth. If that does not work I would try an SMC reset (http://support.apple.com/en-us/ht3964) and a PRAM reset (http://support.apple.com/kb/PH14222)