Based on what you're describing with scams, I would outreach Adult Protective Services. (609-747-7745). He's being subject to a form of elder abuse with these scammers. They can also point you in the direction of how to get him evaluated to determine his competency to make legal, financial, and medical decisions for himself. This will likely also involve in elder law attorney and possibly a case manager.

As for placement for him, there are some options for placements if he does not require the level of care a nursing home would provide (disability housing, independent living, PACE programs can help with living arrangements). APS and the office on aging are definitely good resources to start with that can help you there as well.