According to this government page 50 volts can be considered "Life threatening." However, I read this article which states in the 4th paragraph that you can charge yourself with thousands of volts by rubbing on the carpet. If 50 is deadly, how come you don't die when you generate static electricity? Also, is it safe to use the bottom prong of an outlet as grounding for any project or should it only be used with plugs? Thanks.