Before they finished the door they also made other strange things. They brought metal things and green stuff downstairs. There must have been a source of that green stuff upstairs.
After bringing these green stuff downstairs they started to put all these things together:
In the end there was a new wall. The ones from above argued about sockets, they weren't sure yet were to place the sockets.
The wall felt released at least the ones from upstairs were done with it. It wished the new wannabe wall good luck and decided not to worry anymore.