I have been searching the internet for a sketch called "The Shepherd's Warning" by Keith Waterhouse but with no luck so far. Anyone know where I might find it?
It could be you are looking for the wrong person.
Keith Waterhouse was a newspaper columnist, novelist and playwright not an artist. I think you should be looking for John William Waterhouse
So very sorry! I didn't make myself clear enough. I meant a comedy sketch, comprising a monologue parody of the story of the shepherds at the nativity. Sorry to have wasted your time through vagueness. Thanks, anyway.