In all seriousness, what kind of stuff could actually have you be locked up on a mental facility in the US?
If you're a danger to yourself or others, police can detain you with an APOWW, which stands for Apprehension by a Police Officer Without a Warrant, and hold you until you are deemed safe at an "appropriate" mental health facility. (Most of these places are horrible tbh. Usually filled with the homeless and genuinely mentally ill/unwell people). Back in my EMS days I would dread running calls to these places.
Can confirm. Currently in EMS, we call them Baker Acts in my neck of the woods
Dunno if there are many left in the US but if you answer the question they always ask:
“Do you feel like hurting yourself or others?“
With a "yes" they can recommend you get wrapped up "for your protection" for a short while. Then bill you of course
Ideally, when a medical professional genuinely thinks you are an immediate danger to yourself or others.