How did the maid find all three riddles dead including Tom in Harry Potter and Goblet of Fire?

There is no mention of a maid finding any of the contestants in the Triwizard Tournament dead in "Harry Potter and the Goblet of Fire." The three champions who died were Cedric Diggory, Viktor Krum, and Fleur Delacour. They all died in different circumstances during the tournament.

* Cedric Diggory: Cedric was killed by Peter Pettigrew (Wormtail) in the Triwizard Tournament's final task.

* Viktor Krum: Krum was injured during the second task (rescuing someone from the lake) and subsequently lost consciousness. He was then transported to the Hogwarts infirmary for treatment, where he recovered fully.

* Fleur Delacour: Fleur was injured during the second task (rescuing someone from the lake) and subsequently lost consciousness. She was then transported to the Hogwarts infirmary for treatment, where she recovered fully.

There is no mention of a maid finding any of the champions dead in the book or the film. It's possible you are thinking of a different story or misremembering the details.