Olly Hawes is a British actor with experience on the stage and screen. Years ago, during a student production of Shakespeare's Julius Caesar, Hawes had the titular role. As he writes in The Guardian, he was unprepared for the necessary realism that one of his fellow performers brought to the assassination scene. Due to a mishap, the performer of Brutus stabbed him with a real knife:
There was a sharp piercing feeling. The knife was supposed to have been quietly slipped to me – instead, it had gone into my back. I realised what had happened while acting out my character’s death, and thinking: I have to lie here until the lights go down.
But the show must go on, so Hawes lay still with a blade a mere centimeter from his aorta. When the lights went down, Hawes asked for an ambulance. He left while the play continued with the audience unaware of the accident.
It's unclear who took up the role of Caesar's ghost after Hawes left.
"Every now and then I’d feel a shudder, a sense that I shouldn’t be alive."
I'm inclined to agree with him... They were playing a game of Russian roulette. An unbelievably reckless decision that everyone involved should have known *would* go wrong at some point, and everyone should have refused to take any part in. You can't rely on actors to safely handle deadly weapons while they simultaneously need to dedicate all their focus to their performances.