construction on a door

I went downstairs to put the laundry in;
There was a hammering behind a door.
When I came back to take it out again
I glimpsed a ceiling fan, sawdust-strewn floor;
A crack of inner light spilled down the hall.
The sundered door leaned close on one-by-twos,
A frame, to build the door into a wall,
Raw yellow-gold wood neatly pierced with screws.
From elevator to washing machine,
The doors I pass, the rooms where I don't live--
Inside most of them I have never seen.
But I glimpsed into this one. Please, forgive,
Sweet resident, whose name I do not know:
My eyes beheld a place I may not go.