Structure listing order & classes based on lightswitch value
Whilst I can’t offer the exact template code for an answer right now as I am in bed (have I broke the stack rules?) it might be worth checking out the |batch filter. 

Or taking elements of this answer and making it suit your requirements Making an entry grid with Batch 2,3 (2 in row then 3 in row)

And reading this https://twig.symfony.com/doc/2.x/filters/batch.html