On my first travel trailer the door lock didn't work so I just added a hasp door hatch clasp and used a pad lock. Went to a party at a buddies house and I didn't want to drive home after drinking so I took the TT. I though nothing of just leaving the pad lock hanging on the door. The next morning I woke up to find some friends had locked me in the TT !!! :B
The door had a window in it and the screws for it were on the inside. Using my Swiss Army Knife I was able to remove the screws and take out the window. After that I reached out and unlocked the door.
I never left the pad lock hanging on the door again. :B