Tempted to do this in my locality with chalk. Instead write this:

"If you're reading this, you've been in a coma for almost 20 years now. We're trying a new technique. We don't know where this message will end up in your dream, but we hope it works. Please wake up, we miss you.",

https://github.com/minimaxir/big-list-of-naughty-strings/blob/db33ec7b1d5d9616a88c76394b7d0897bd0b97eb/blns.json#L507

Maybe make it personal and add a common name in my city 😂