If you are touching someone who is hit by a taser will you be electrocuted too?

Probably not. For a bystander get the 5 seconds of high voltage when touching somebody else who is getting taser'd, the bystander would have to conduct electricity very well. The electricity wants to go from one prong to the other, so travels in between the prongs. However, if the main person got hit with one prong and the bystander with the other prong, the electricity would have to travel through both people.