Question

bring out element of humour in the canterville ghost

Answer 1

The Otis' twins had almost sworn to plague the poor Ghost.
Whenever they had a chance,the would throw pillows at his head or have ago at him with their pea-shooters.
They would balance a jug of cold water on a door, so that when the Ghost opened it, he would get drenched.
The twins even went to the extent of constructing a false scepter with the help of a hollow turnip, a broomstick and a kitchen cleaver.
So frightened was the Ghost on misconstruing the false scepter for a real one that he fled to his room abandoning all plans to frighten the Otis family. The twins would also shout "Boo" into the ears of the Ghost when he was unaware of the presence of the twins.
Thus, the defiant nature of the twins and the pranks they play on the Ghost added more humour in the novel.

hope it helps...