It's simply a lot of one-frame cuts between two shots. Personally, I'd do it in an NLE like Adobe Premiere, rather than AE.
If you want to do it in AE you coud easily use a Ttransition effect with hold keyframes alternating the Completion parameter between 0 and 100%. Or you could just use hold keyframes on Opacity. Either option can be saved as an Animation Preset to reuse easily.
The Strobe effect is your friend...
Thanks for the response Andrew and Mylenium. Mylenium are you speaking of the Strobe Effect, do you mind sharing how create that look?
Nvmd. found out how to do it. super easy . thanks so much .
if anyone else wants to know .
select strobe effect
set strobe duration to .02
set strobe period to .04(never less than the strobe duration)
and make sure strobe operator is on 'copy'
.. super easy.