[ApicalDendrite]

Ferdinand Demara impersonated a surgeon on a Canadian naval ship during the Korean War. He performed a number of successful surgeries and was only caught because of a newspaper article about how he had successfully removed a bullet from a wounded soldier.

https://en.wikipedia.org/wiki/Ferdinand_Waldo_Demara

[eru]

Highly interesting! Following a link from Wikipedia, I saw that his biography is available online at https://archive.org/details/greatimpostor010210mbp