How to find addresses for free - can’t find my brother!

Other than white pages, does anyone know of a website to find updated info on someone for free? No one can find my brother, his wife or kids, and are worried about them. His wife’s family can’t even contact them. I know they’re alive because my brother is under some fake name on Facebook and constantly posting. They have 5 kids and are not able to hold steady jobs or afford his oldest son’s insulin for his diabetes, and honestly we want to make sure they’re okay. I can’t find their current address.

We have tried to get social services involved, which didn’t go as planned, but we really just want my Dad to go do a wellness check.