case

Hello.

I posted the same question before, but there was no reply.
I would like to know the difference between the below phrases with the word "case". It is very helpfull if I can get any example sentences for these.

- in case of
- in the case of
- in a case of

Thank you!

[Tdol]

It has to do with how specific you are being:

In case of fire, please leave in an orderly fashion. - General.

In a case of arson, what sentence do you think would be appropriate.- Here I am talking about a single case as an instance of arson.
In the case of Enron- here I am referring to a specific occurence and not as an example of anything.

Thanks!
I understand it, and your reply is really helpful!

Mit