Earlier quoted context omitted.
It’s a little writing trick I leaned from (I think) Orwell. Any time you’re about to use a common metaphor, try to tweak it. You’ll catch readers off guard, which piques their curiosity. It’s a fun game, too. I wish I’d used “the cat’s out of the hat,” but I didn’t think of it till later.
What you are describing is also known as an eggcorn. https://en.wikipedia.org/wiki/Eggcorn
The 2nd example also loosely falls under the classification of malaphor.