“A paraprosdokian is a figure of speech in which the latter part of a sentence or phrase is surprising or unexpected in a way that causes the reader or listener to reframe or reinterpret the first part.”
The last thing I want to do is hurt you. But it’s still on my list.
To steal ideas from one person is plagiarism. To steal from many is research.
I’ve had a perfectly wonderful evening, but this wasn’t it.
I like going to the park and watching the children run around because they don’t know I’m using blanks.
More at Wikipedia.