MacBook Pro trackpad goes erratic when paper touches it
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)