I guess confusing a particular pair of words happens more often to non native speakers than to native speakers, but maybe some of you do have similar "false friends" whom you keep switching. I'd like to read them.

Mine are, in particular,
hospitality and hostility
as well as
crutches and crotches.

So, if I ever thank you for your hostility and express my relief over the fact you're not walking on crotches anymore, do not mind me.

When in Malaysia I went to the doctor as I had headaches...

The Malay for this is sakit kapala but I said sakit kalapa which means sick coconut... Causing much amusement.

PhD Student: Research information sheet

There once was a man named Bruce
Who liked to sit on a spruce
He ate lots of chowder
And yelled at me louder:
"I'm talking to YOU, Mrs. Hughes!"
--> The Literary Genius: Mowgli

A friend of mine has terrible trouble with Prostate and prostrate. This induces a lot of talk about cancer lying on the floor...

Damn Spider pig

My grandmother, at 88, still insisted on doing her own shopping often with hilarious results which we attributed to the adverts on the commercial channel of the 60's.
I remember she came back one day with six tins of a well known cat food in her shopping and spent nearly half an hour looking for her favourite chocolate biscuits. She'd asked the shop keeper for Kit-e-Kat instead of Kit Kats.
Some of her other gems were her continual reference to to Typhoid tea (Typhoo) and Polio mints (Polo's).

I want to die peacefully in my sleep, just like grandpa. Not screaming and panicking like his passengers.
Don't drink and drive from The Lancre Tavern

My friend, a number of years ago in science class, was reading a passage from the text book. He pronounced organism as orgasm, to much amusement!

Ah yes, organism and orgasm - a combination messed up many times in our Home Economics classes (sometimes deliberately)

My family have a habit of mispronouncing words, not mixing them up with others. For example, Tiara and Tarara. Attic and Ackit (that was me I'm afraid). For years, my uncle Flor was called uncle Flower by my sister. My aunt constantly calls the chocolate Galaxy bars Gala-x-y bars. We haven't had the heart to correct her. Plus it's just too funny. Thankfully, the only one that always gets on my nerves was never ever mixed up in our family; hospital and hostable. A mixup that is all too common around my side of the country.

But the one thing that yet another aunt kept mixing up was Pedestal and pedestrian.

In an english class the teacher was writing on the board and I was reading outloud along with him and I accidently pronounced superfluous super-flew-us. The class found this quite hilarious...

PhD Student: Research information sheet

There once was a man named Bruce
Who liked to sit on a spruce
He ate lots of chowder
And yelled at me louder:
"I'm talking to YOU, Mrs. Hughes!"
--> The Literary Genius: Mowgli

My mom told me she was excited for the new Star Wars movie to come out, because she has always been a "Trekkie" I had to explain Trekkie = Star Trek not Star Wars.

Time flies like an arrow
Fruit flies prefer a banana

I bet you've upset thousands of "Trekkers" out there now. They hate being called Trekkies!

I want to die peacefully in my sleep, just like grandpa. Not screaming and panicking like his passengers.
Don't drink and drive from The Lancre Tavern

lol On behalf of my Mom I Sincerly appoligize to all trekkers.

Time flies like an arrow
Fruit flies prefer a banana

Some of Ba's teachers had a little trouble with the pronunciation of certain words. For example, once a teacher was talking about the "Honor" of the store. Ba and his classmates tried to parse this for several minutes, before they finally realized she meant Owner.

Then there was the wheel in the ocean...