dulcimer42's post reminded me of a joke I heard in a Pub in Ireland, told by Ger Collins a well known fiddle player. Not really malapropisms, more a case of euphemisms maybe.

Pat Murphy a very shy farmer married Mary Cronin and on the wedding night Pat's shyness got the better of him, so when Mary who'd gone up to bed called to Pat he said he would be up as soon as he'd finished his cigarette. Half an hour passed and Mary again called to Pat. "I'll be up shortly" he said, "I've just got to check on the cows". Anyway, another half hour past and when Mary called, Pat decided he'd have to make the effort, and made his way slowly up to bed.

Mary said "Come now Pat, are you going to get undressed or not?" So slowly, Pat began to remove his shoes and socks. When Mary saw Pat's feet, she said "You've the strangest toes Pat, how did they get like that?
"Sure" Pat said "I had a bad case of Tolio when I was a small child"
"Don't you mean Polio?" she said
"Not at all" says he "Me mother definitely said it was Tolio"
At that, Pat slowly undid his belt and his trousers fell to the floor. On seeing Pat's knees, Mary exclaimed "You've very strange knees Pat, how did they get like that"
"Ah sure" he said "I had a very bad case of neasles when I was a child"
"Don't you mean measles?" said Mary
"No, no, me mother said it was a very bad case of neasles." Pat replied.
"Come on then " Mary said hurry up and get undressed and get into bed."
Pat began very slowly to remove his underpants, whereupon Mary began to laugh.
"What are you laughing at" said Pat
"Well" said Mary "It's very clear to me that as a child, you had a dreadful case of small pox!"