What is the reason why an unfamiliar girl came to my house for one night?

Unfamiliar girls may come to your house for one night for various purposes.

1. Travel or business trip: If she comes to travel or business trip, she may need to find a local place to stay for one night.

2. Ask for help: She may need your help, such as staying overnight or providing you with some temporary accommodation.

3. Emergency: If she encounters an emergency, such as having nowhere to go or encountering other difficulties, she may need your help.

4. Seek comfort or companionship: She may feel lonely, afraid or need a comforter to accompany her through a difficult night.

5. Overnight: She may need to spend the night because she has nowhere to go or doesn't have enough money to stay in a hotel.

The specific situation needs to be decided according to the specific situation between you. If there is no intimate relationship between you, it may not be appropriate for her to come to your house for one night. You should also consider your own safety and privacy. If you feel uncomfortable or suspicious, ask her in time and let her leave.