Two that I've seen that made me laugh were "escape goat" for "scapegoat" and "water under the fridge" for "water under the bridge", I use these malaprops intentionally now.
I mean "scapegoat" is a shortening of "escape goat" so probably at some point in history there were grammar pedants complaining about kids these days saying scapegoat instead of escape goat.
> The English scapegoat is a compound of the archaic verb scape, which means "escape," and goat
