Key frames(or expressions that randomize) the opacity,scale and position properties with motion blur turned on.
This tutorial tackles what you want to do and a bit more.
http://ae.tutsplus.com/tutorials/motion-graphics/make-a-glitchy-interface-a...
Johnny Cuevas, Editor
Thinkck.com
"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.