That's good to know, but it leaves you without many options, since all the experts also suggest not to confront them with reality. So how to interact with somebody who as a psychosis and sees a complete twisted reality?
Call an ambulance. Acute psychosis needs immediate treatment, they may easily hurt themselves or others. The psychosis can be stopped with one injection, don't prolong their suffering. Before the ambulance arrives, try to reassure them that they are safe, there is peace around them and help is on the way. Once the ambulance arrives, go away - it might get messy.
I am not sure from which country you gain your perspective, but in Germany it's not what's gonna happen. Your human right is the highest good, and police or any doctor is only permitted to force you to take drugs or put you in a clinic when you are acute suicidal or you harm others.
Unfortunately I know that first hand.
A person with delusions like that is a risk to themselves and others.