Ghoul (/ɡuːl/) - an evil spirit or phantom

I tried not to be mediocre when it came to deciding on my web address. Whether it's creative or not is not for me to judge, however I wanted to make it relative to the theme of the whole blog. 

Whilst I was looking up An Inspector Calls, I came across a website which was talking about the meaning of the names of the characters and discovered an interesting conception of the use of Goole.

It explained that the inspector's power and knowledge is never properly explained, and that he may not even be a real person, just a ghost or spirit of a religious or moral figure (which ties in with other ideas in the play). 

On the other hand, the dictionary definition of ghoul (as seen in the title) may suggest that the inspector is an evil person, or a lingering evil conscience which is present in all the other characters. This could easily be applied to the ending of the play when the Birling family realise that the whole investigation was a hoax, but then receive a phone call with the same details of the suicide they were informed about at the beginning . Perhaps their conscience was teaching them a lesson, or maybe their conscience was mentally preparing them for the news the second time around.

So did Priestley use this play on words of Goole and Ghoul to represent the inspector as a ghostly figure? Or is it just a big coincidence?