In Aussy we do not have squirrels in our neck of the woods - but possums!!! 

Our old farm home, built 1933, weather board, needed attention.

We got it clad [over the weather boards] with insulated vinyl cladding. The contractors altered something around a gable, and some how the possum found that he could access the roof space.  Set up home - leaving after sundown, and coming home before sunup - noisy both directions!

Tried traps, he was too wary! Bait - also too canny to eat that. Got myself up into the roof space, could see him, but not get 'at' him. Thought of waiting until he went out in the evening, then block his point of in/out.

Probably 20 years ago, but can remember a terrible ruckus when he arrived "home" just before sunup. He literally tore his way back into "his" space!

End of story - he died of lead poisoning. [.22 rifle!]

Then I re blocked the hole!