Dealing with a conspiracy theorist advice

[HugeHons]

I’ve a brother who has gone batshit crazy as a conspiracy theorist. 
Met him last night. All on about the illuminati controlling the world and that Donald Trump is a decent bloke.
This lad used to be ok, but now he’s typical in that he rolls his eyes if you aren’t on the same page is permanently angry and completely bonkers. 
He’s a 56 year old bloke who hadn’t read a book since he did his school exams, but done ok work wise as a builder.
I found him a condescending cunt but managed to bite my tongue. 
I’d suspected for a while he’d gone down this path, but just wondering if any of you have any advice other than stay away from him?

I’ve got an old school friend on FB ( known her for 50 years!) she was always quite level headed, but she’s a massive conspiracy theorists and laughs at me because I read the BBC News page. Some of her conspiracies are as follows:

Maddie McCann was kidnapped by the ‘establishment’ so they can inject us with tracking devices

TV Doctor Michael Mosley worked for MI5 and has gone into hiding because of the vaccine roll out 

The Covid vaccine is/was killing everyone 
Covid doesn’t actually exist
Humans can’t catch viruses anyway

Around 10 people control the world ( even control Kim jong Un/Putin etc)

Climate change is a scam and the Hollywood fires was to get rid of actors so they can use AI instead

Flying abroad will be banned in 2025 ( oops)

The MP Jo Cox wasn’t murdered and her name sounds like ‘Joke OX ‘ which has some other conspiracy meaning 

Plus many more I’ve forgotten. I tend to ignore her now but sometimes her posts are a good entertainment.

But me reading a few main headlines on the Beeb is a problem for her