Lots of ways to create that, couple of places to start are to using shape layers and adding a "wiggle paths" animator. Also look at the Stylize > Roughen Edges effect. And some of that is done with old school animation.
Johnny Cuevas, Editor
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.