I read this in a Sci-Fi anthology book about 20 odd years ago.
The gist revolved around the idea that humans were slaves to their handheld computers. Basically no one thought for themselves anymore. Anyway, the handheld computer gets tired of being controlled so it starts to give the user travel instructions that the user blindly follows. In the end, they are caught and the user gets a new handheld that "worked".
This may be "The Creature from the Cleveland Depths" by Fritz Leiber, though the details don't quite fit.
“It goes on your shoulder under your shirt,” Fay explained, “and you tuck the pellet in your ear. We might work up bone conduction on a commercial model. Inside is an ultra-slow fine-wire recorder holding a spool that runs for a week. The clock lets you go to any place on the 7-day wire and record a message. The buttons give you variable speed in going there, so you don’t waste too much time making a setting. There’s a knack in fingering them efficiently, but it’s easily acquired.”
Fay picked up the tickler. “For instance, suppose there’s a TV show you want to catch tomorrow night at twenty-two hundred.” He touched the buttons. There was the faintest whirring. The clock face blurred briefly three times before showing the setting he’d mentioned. Then Fay spoke into the punctured area: “Turn on TV Channel Two, you big dummy!” He grinned over at Gusterson. “When you’ve got all your instructions to yourself loaded in, you synchronize with the present moment and let her roll. Fit it on your shoulder and forget it. Oh, yes, and it literally does tickle you every time it delivers an instruction. That’s what the little rollers are for. Believe me, you can’t ignore it. Come on, Gussy, take off your shirt and try it out. We’ll feed in some instructions for the next ten minutes so you get the feel of how it works.”
Anyway, the handheld computer gets tired of being controlled so it starts to give the user travel instructions that the user blindly follows.
The dazed look slid aside from Fay’s eyes. He was gasping less painfully now. He sat up, pushing the towel away, buried his face in his hands for a few seconds, then looked over the fingers at the two of them.
“I’ve been living in a nightmare for the last week,” he said in a taut small voice, “knowing the thing had come alive and trying to pretend to myself that it hadn’t. Knowing it was taking charge of me more and more. Having it whisper in my ear, over and over again, in a cracked little rhyme that I could only hear every hundredth time, ‘Day by day, in every way, you’re learning to listen … and obey. Day by day—’”
In the end the "ticklers" are persuaded to leave humans alone and find their own destiny.
