Police were called to the house in Offenburg by the resident and her neighbour after the woman, who had too much to drink, wandered in proceeded to take a nap. The door had been left open to let fresh air come into the house.
"She came into the house and just made herself at home," a police spokesman from the Offenburg police station told The Local.
Once in, she undressed, took a shower, dried herself and laid down in bed to sleep it off.
The resident of the house was home the whole time and was in a state of shock, unsure how to react to the uninvited guest, police said. "She saw everything happen, but wasn't sure what to do."
Only after the woman had gone to sleep did the senior consult with a neighbour and phoned for help.
Arriving officers abruptly woke the slumbering stranger and took her to the station after giving her time to get dressed. She told officers that she had mistaken the house for a friend's.
The woman is known to police, though this is the first they've had to pull her out of someone else's bed.