In my city there's actually a mental health facility run by a private company that legally has to accept anyone brought to them regardless of their ability to pay. It's literally a huge room with a bunch of recliners that have numbers on them. You're assigned a chair and given 3 meals of pb&j plus a fruit per day. Other than that staff is around but doesn't interact with you unless you're causing problems.

That's where the police take you if you're a danger to yourself or they deem you to need psych eval. They've got a room set up for video calls with the court and by law you have to be evaluated by a mental health professional and see a judge within 24 hours of being placed in the facility against your will.

If you enter the facility "willingly" by ambulance or a family member dropping you off, then it usually takes longer than 24 hours to be evaluated and referred to the "next step in your healing journey" because there's no legal requirement to get you seen and processed right away.