Not a #fourwordhorrorstories but something I wrote on my Weird Birdsite account recently:
A horror story:
I fall asleep, head cradled in the scanners.
I awake, to still-frail flesh.
"Freedom," says the copy on the screen.
Not me.
(Copied from me, here: https://twitter.com/EMForestry/status/924784416852926464 )
Of course, only after posting do I realize I really should have started the hashtag #posthumanhorrorstories instead. :-)