Way back in the 1980s, I had one of those electronic typewriters that were a halfway house between a typewriter and a word processor. (You could type a couple of pages straight into the memory chip, such as a format for a bulk letter, and then you could print it off as many times as you liked.) Very whizzy for 1983!
So I was at my girlfriend's house, and we'd just come back from shopping, and we became aware of a distant rattling thunder going on upstairs. And my girlfriend went up to investigate, and after a while she came down looking very spooked. She'd found my typewriter hammering away furiously, all on its own, with no paper in the roller, of course. So she'd fed a sheet into it, and it had produced what appeared to be part of a crime novel. The same five or six cryptic paragraphs, over and over again. Quite clearly, somebody "on the other side" was trying to communicate with us about who dunnit, and where the body was buried!
Well, it would have, except that the ectoplasmic fog had intermittently got in the way, so that there'd be curious gaps and mis-spellings and non sequiturs in the story that was being related so insistently to us. It took quite a while for me to figure out what the hell was going on.
Which was that the rom chip in the typewriter had been embedded with a test sequence that had been laboriously typed in by a Japanese who didn't speak English and who couldn't detect the linguistic shortcomings. And that some random blip in my girlfriend's household power supply had set off the test sequence. And that this typewriter would have carried on telling the wordless story until it wore out the rubber in the typewriter's roller, or until it caught fire, or until the neighbours called the police.(Dammit, we might have been away on holiday!)
We kept the machine permanently switched off after that.
BJ