A.B. Cox, in Jugged Journalism (1925), suggested that Arthur Conan Doyle might hand over the writing of a Sherlock Holmes story to P.G. Wodehouse:

Holmes and the Dasher

It was a pretty rotten sort of day in March, I remember, that dear old Holmes and I were sitting in the ancestral halls in Baker Street, putting in a bit of quiet meditation. At least Holmes was exercising the good old grey matter over a letter that had just come, while I was relaxing gently in an arm-chair.

‘What-ho, Watson, old fruit,’ he said at last, tossing the letter over to me. ‘What does that mass of alluvial deposit you call a brain make of this, what, what?’

“The letter announces that Cissie Crossgarters will be rolling round to see jolly old Holmes,” explains Richard Lancelyn Green in The Sherlock Holmes Letters. “It is all dashed rotten and pretty thick, but when Holmes has splashed a little soda into his glass of cocaine, he heaves himself out of his chair and trickles out to her. ‘What ho!’ says Bertie Watson when Holmes returns. Everything is top-hole and the chappie Holmes announces that Cissie and he are engaged to be married.”

Miles Kington once wrote a Holmes adventure in blank verse — it’s called “The Case of the Danish Prince”:

SHER:  But here, unless I'm much mistook, comes one
       That needs our aid. A case at last!
       (Enter to them HAMLET)
HAM:   Which one --
SHERL:               Of us is Holmes? 'Tis I. This gentle here
        Is Watson, my devoted friend and colleague.
HAM:    Good morrow to you both. You do not know me --
SHERL:  Apart from knowing that you are a prince,
        From Denmark, I would hazard, and a solitary,
        That you take snuff, have lately been at sea,
        Were frightened by a horse at five and now
        Are sitting for your portrait, you are a stranger.
WATS:   Good heavens, Holmes!

The full text is here.