Interesting thread Veridical
I think what you want to know, really, when the door knob starts shaking is if there's any kind of danger to yourself. There's a fear or worry that something dangerous is happening and that needs to represent itself somehow in the mind - is it a break-in? Is it a ghost?
From the way you write, it seems these thoughts were pretty instinctive but then you overcame them with rationality. I also force myself to think rationally when stuff like that happens. :p