I live in a 2001 double-wide mobile home. My spouse and I would love to install our ceiling fans from our previous home, but have been told that the ceilings in our home are not made to support the weight of the fans. We have angled ceilings. Is there any kind of support box that is made to help support ceiling fans for mobile homes.

I don't know about specific brackets for mobile homes. I know they make fans designed for mobile homes, I have also seen regular fans mounted in mobile homes.

Google came up with this, but it seems the same as the bracket for normal homes:

Mobile Home Repair - Adding a ceiling fan