A malapropism walks into a bar,
looking for all intensive purposes like a wolf in cheap clothing,
muttering epitaphs and casting dispersions on his magnificent other,
who takes him for granite.
Like the person I my-own-self heard refer to “the cold face” (vice “the coal face,” meaning “at the point of the (hard) work”), many of us know words and expressions that we’ve only ever heard, never read, and that we can scramble ever so slightly as a result.
Add that to the ever-so-helpful auto-completions from word-processing software and, for all intensive purposes, you can generate malapropisms that spelling check will never find.
Never take a good copy editor for granite, but do stand well back if they start muttering epitaphs.