What humour is hidden in the 'Open Window' and why is it humorous or ironic? Explore the humour and describe it in detail.

Some readers might find humor in Mr. Nuttel's reaction to Vera's ghost story. He came to the countryside to settle his nerves, and ironically ends up more upset than before. Vera's joke, however, isn't funny at all, as her story played upon his insecurities, which in turn, caused him to suffer another breakdown.