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The ceiling is gypsum board, right?
If the hole is not very large, then cut the hole neatly and deal with it according to the appearance of the maintenance opening.
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Each is made into two appropriate small sliding doors, which look awkward and inconspicuous, and you can continue to climb next time if this happens.
The owner of the building is preparing to re-pour the bathroom floor.
Find a decorator, smooth out the hole, put water on it, if the hole is big, embed it in a cabinet If it's small, put a soap, roll paper or something.
It may be a reserved hole for ventilation. The bathroom should be kept well ventilated, so that there is no smell!
Seeing your second picture, I thought that the upstairs bathroom waterproofing was not done well
If you dream of your own bathroom, then you will have a windfall.