So, after adding new mods to my game. (Extreme Violence, skygazing etc) Basically many of the Sacrificial Mods. Depending on what custom content items I put in my game, it appeared that my sims had light squares all over their bodies. It didn't appear in CAS but when finalising the household (Like Shown in the photo) and when in build mode and live mode.
Someone, please tell me they know how to fix this!!
I have a word document attached with a photo of what the glitch looks like.