My version of the backrooms is a place where you can time travel within each level, and dimension travel by no-clipping into another level.
On each backroom level guards a landlord, the one who maintains and monitors the backrooms and it's inhabitants, aka ghosts.
Ghosts are when a person died yet their consiouness is still alive an hasn't moved on into the limbo to be recycled into ideas for future generations in the Cherubim Dataset of the program Eden.