When your doorbell rings in the middle of the night it is almost always not a sign of something good to come. When a stranger is outside yelling for help it puts you in a dilemma and how you react could mean the difference between life or death. I think the prudent thing would be to call 911. If you decide to open the door be prepared for another person to attempt to enter the home. Watch Comedian Sebastian Maniscalco if you need a laugh now.