The house is built on an old monastery …
Your reasoning is the dog is high on drugs coz it’s an ex-prison dog …
Try to observe if it howls again and note the time and place.
I don’t believe in ghosts but it does make me get goosebumps thinking about it as I can’t rationalise it or make a logical explanation.
You cannot rationalise because you have no such concept hence you cannot logically explain the situation. Yes, the old lady is there but harmless as she has not disturbed anyone.
The only understanding you have is the corner of the room that is unexplained.