Hello ArthurWinthrop: I noticed this is your first post here on PC. So... welcome to PsychCentral.

We here on PC cannot offer mental health diagnoses. Plus I'm not a mental health professional. So there's really not much I can offer with regard to what may be going on with your relative. On the surface, at least, it sounds as though your relative may be struggling with schizophrenia. There's a forum, here on PC, dedicated to the subject of schizophrenia & psychosis. Here's a link:

https://forums.psychcentral.com/schi...and-psychosis/

One additional forum that may be of interest would be the partners of people & caregivers forum:

https://forums.psychcentral.com/part...ivers-support/

Based on what you wrote, it sounds as though your relative may be experiencing delusions. Here are links to 7 articles, from PsychCentral's archives. They discuss delusions & what to do as well as what not to do with people who are delusional, plus treatment options. The first article is by our host Dr. John Grohol, Psy.D.:

15 Common Cognitive Distortions

6 Dangerous Delusions Someone You Know Might Have | Caregivers, Family & Friends

10 Things You Should Know About Delusions | Caregivers, Family & Friends

https://blogs.psychcentral.com/careg...is-delusional/

https://blogs.psychcentral.com/careg...has-delusions/

https://blogs.psychcentral.com/careg...hout-fighting/

https://psychcentral.com/disorders/d...der-treatment/

I hope you find PC to be of benefit.