I have...
Messages to exs just to let off steam.
Or even compose how I'd respond to my "imaginationships" (please don't laugh).
Never send them. They're not part of any actual social conversations. They're not actually draft messages, either.
If there was some criminal case there is no way they could be connected with social reality.
(those kisses never happened)
I also do some manifesting and journalling. I like writing as if amateur poetry. It looks dramatic but isn't "real".
Lots of random stuff written down which isn't reality but me processing intense subconscious thoughts and feelings and emotions.
Or imaginary responses.
A lot of women do a Sylvia Plath or Northanger Abbey and journal and write stuff which isn't really what happened.