The owner of the house didnt even notice until police came

https://www.is.fi/ulkomaat/art-2000011477434.html

Man lived alone in a "single family detached home."

There was a basement level accessible only from the outside, meant as a storage space.
But the owner of the house had been keeping the storage compartment empty.

One day, nobody knows when exactly, a man had noticed the storage door open while walking past the house and he realized he can investigate whats in there.

He noticed it is empty and moved to live in there. He changed the lock.

The actual owner of the house sometimes wondered what could be the noise that comes underneath his house..

One day he tried to open the door and noticed his key doesnt work.

Police came, broke the door and found a man who isnt supposed to be there. He has been arrested by "breaking into a house" charges but there is no such a crime as "living in a house without permission".