Perhaps the most famous instance of a sentence that exhibits semantic pathology is the Liar: 'This sentence is false'; if the 'this' strikes you as problematic --
(1) (1) is false.
But there are many other types of semantic pathology, such as the 'heterological' paradox and the so-called 'truth-teller': 'This sentence is true.' My colleague James Woodbridge is doing a lot of interesting research in this area; check out his work if you are interested.
This is not a serious post about semantic pathology, but rather just a field report. I sometimes wonder whether these examples like the truth-teller are all that important, since it's hard to imagine circumstances under which speakers might utter it. But I think I may have found a couple of instances of something akin to the truth-teller "in the wild":
(i) A couple of weeks ago, I went to see Spamalot, the musical adaptation of Monty Python and the Holy Grail. One of the songs contained (something close to) the following line: "This is the song that goes like this."
(ii) In the instructions for the Pennsylvania state tax forms, I found (something like) the following:
"You are eligible for the Tax Forgiveness credit if you meet the following requirements:
3. You meet the eligibility requirements for the Tax Forgiveness Credit.