My favorite anecdote about him, which was not widely known, involved what used to be called "nut letters." Before the internet, if you were a famous scientist, particularly a famous physicist, you would receive actual letters from people all over the world asking for help with their perpetual motion machines, time travel devices, and similar nutty theories. Having worked on black holes, gravity, general relativity, and the bomb, Wheeler was quite a nut magnet. He was also blessed with a bit of OCD in the way he organized and categorized all his notes (his annotated bibliography for Misner Thorne and Wheeler Gravitation filled many shelves in the library). John didn't just receive nut letters. He received, read, organized, filed, classified, and acted on nut letters. His preferred response to them was "I'm afraid I'm not very knowledgeable in the area of your work but I believe you should contact _____ who is working on similar conjectures and may be a good source of additional insights" at which point both parties in that conversation would be so ecstatic to be talking with someone recommended to them by the great John Wheeler that they'd never bother him again. While in grad school, I happened to read an article in the New York Times on a perpetual motion machine (their weekly Science Times section was fantastic but did occasionally step into pseudo science topics). At the end of the article the main researcher thanked John Wheeler for having introduced him to the theorist who had helped him refine his understanding of the mechanisms at play in his invention, and I couldn't help but smile at the wonderful successes of John Wheeler's nut dating service.
In this episode of Tested Joe DeRisi describes how a random letter from a snake owner led to some interesting published results in molecular biology.
The title isn't wrong, either, this one is terrifying (so far).