I think there must be quite a few of these. Some are derivatives of each other and do mean the same thing, some are usage driven, and some are just coincidence. I get reminded when a word in a book seems a little off, like:
Hearty, hardy
Stanch, staunch
I had more but these things just fly in and out of my head. What say you all?
There are lots of these. Sometimes the correct word is uncommon, so people tend to use the more common but incorrect word. Like “mute” instead of “moot”. Others that peeve me:
compliment / complement
averse / adverse
discreet / discrete
affect / effect
flaunt / flout
home / hone (as in “home in on something”)
prosecute / persecute
tack / tact
For me, the first time I ever saw it was late '90s. Buffy The Vampire Slayer fanfic, actually. I saw a lot then (I think I even checked to make sure all weren’t same author). And since then, I’ve seen it every so often, in various places online. I agree that it’s not a mistake I’ve ever made myself. So I’d never seen it before the internet-era, either.
I have an entire book of these, the wonderful Penguin Dictionary of Confusibles
It not only gives pairs (and triplets, and quadruplets) of words of similar meaning, but also parses the differences between them.
Sadly, it was published in 1980, to my knowledge hasn’t been reprinted, and is this Out Of Print. Your best bet is Alibris or Abe’s or Amazon or some other online used-book source.
A brake is something you use to stop a moving vehicle. If you are braking, you are slowing down.
A break is an interruption of some kind (a break from work, a break in a structure). If you are breaking, you are falling apart.
“Damp” means to reduce or mitigate. It’s often used in engineering contexts to describe the reduction of oscillations or movement in a system. On your car, shock absorbers damp the movement of the suspension; dampers are doors in HVAC ducts that control the movement of air.
“Dampen” means to moisten. Rain dampens the street. Your mom dampens a washcloth with her own spit to wipe that smudge off of your cheek.
Also, not what the OP asked, but my voice-to-text for my voicemail once came up with “cat wrecked” when my mother left a message about her cataract surgery.
Also “expostulate” does not mean “guess,” just because it sounds like “postulate”-- which doesn’t really mean guess either, but it’s closer.