Meaning of "My what a joke!"


Could anybody please tell me what the following expression means?

My what a joke!


Where’s the context? :cry:

Without the context :x , I’d say two possibilities would be:

  • My goodness! That joke was excellent!

– OR –

  • My goodness! That’s ridiculous!


So could we use My this way?

I mean both in written and spoken English?

1- My what a beautiful house!
2- My what a mess!

Is the use common?


Probably more likely in spoken English, but I don’t see why it shouldn’t also be written. If I wrote it, I’d probably add a comma after “My”.