Is there assistance to help with home repairs?

I would check with the city. My MIL had her house refurbished by the city of Mesa in Arizona. Different communities offer helps. You might also ask at the area churches, community center, agency on aging.

fkeller, there usually comes a time when an older person cannot afford to maintain their home on their monthly income..... they need to downsize, sell their home. With home ownership something is usually on the fritz. Or the owner has memory issues and is unable to realize the place needs repair.

Your Uncle might prefer to live at a VA home where he is around fellows who were also in the military.

I found this article that will be helpful: https://www.agingcare.com/veterans-assistance

The County Health Department might help with fumigation.

Help him, or do it for him, by contacting either a County Veteran's Service agency, or the AZ State Veteran's Agency if there is one. Or contact a service organization such as the VFW or American Legion, and ask about benefits to which he might be entitled.

These services are all free; don't get tricked into hiring someone to qualify him with the VA.

The County might also know of a place he can live while his trailer is being fumigated.

You can also try contacting local senior centers to ask if they know of shelters.

The city in which he lives may get federal funds through grants to help with emergency repairs. That's something to check out. I don't recall which department in my city handles this; it might have been Code Enforcement, or the Building department.

Habitat for Humanity rehabs houses.

You can also check out these posts on similar subjects:

https://www.agingcare.com/search.aspx?searchterm=home repair help

He gave up over 20 years for his country; his country should do something for him.