I, too, have a tale of someone convinced their PC was haunted. My grandmother asked me to take a look at her friend's computer. She had two problems.

One that the " and @ keys were swapped. I don't know why she mentioned that the last person who tried to fix it was American but that's an instant fix. No shade on Americans, you probably don't have much call to change keyboard settings to en-GB from Microsoft defaults.

The other was it would boot up at random times, day or night, and it would spook her. No rhyme or reason as to when. It was early on in my IT career so I was still geeking out over everything, every new motherboard I bought I'd be exploring every BIOS option before even thinking about installing an OS. One option I'd never had to use but had intrigued me was Wake On Ring. And she did have dialup.

Wake On LAN requires a Magic Packet or some other protocols. But I reasoned WOR might be simpler and the telco sending diagnostic pings that would trigger it (it's a long time ago, I never bothered to look it up or even if I thought to ask if the phone rang at the same time). This computer does indeed have a WOR option which I disable. We won't know straight away if it works so I say to let me know, which she does after a week and is confident it's stopped.

And that is my IT exorcism story to add to the pile. Does everyone have at least one eventually?