this is tough to search for (most references to images flickering online are attempting to remove them)
i did find this though: http://www.webegg.co.uk/flicker-effect-with-jquery/
seems like a good starting point if you want to accomplish this with jquery. on the other hand if youre only supporting modern browser you can do it using pure CSS.
if you wish to go that route, here are mr coyier’s css keyframe animation code snippets to get you started: https://css-tricks.com/snippets/css/webkit-keyframe-animation-syntax/