This is a hard to find 7 minutes long cartoon from 1951.
The cartoon is called Wearing of The Grin and it’s from Looney Tunes.
Porky Pig is a weary traveler who must stay the night in a foreboding castle. There, the castle’s caretaker warns Porky about the leprechauns that roam the grounds tricking wayward travelers.
You can possibly find on HBO Max.
https://holidayfilmreviews.blogspot.com/2021/03/looney-tunes-wearing-of-grin.html
https://en.wikipedia.org/wiki/The_Wearing_of_the_Grin
