There is no such thing as a "friendly phone call" at the middle of the night from a police officer you don't know.

If it's just a phone call, why involve the police at all? But if that doesn't work, and it's critical that someone is woken up and no one is near, I could see the police as a reasonable option.

I agree with GP that my first instinct would be "lawyer", but I'm imagining the police at the door saying something like "hey we're here to inform you there's an urgent xyz, we'll now be on our way" and leaving. At that point that's the police matter resolved, no?