No I haven’t had anything go horribly wrong. I have done experiments where the results didn’t tell us anything new, but that just makes you want to design the next experiment. The equipment I use to measure brain activity is very safe and it can’t hurt anyone.
Sorry I haven’t got any horror stories, but most of the time science is very safe.
I’ve never had an experiment go ‘horribly’ wrong, but I’ve had disappointing results where either I’ve made an error in the design, or I couldn’t get enough people to test, and so my results have been meaningless. And as I may have mentioned in the odd chat, once I got a nasty electric shock from a laptop I was using to run my experiment, but otherwise nothing dramatic!