I've heard of folk doing this, but in well over twenty years of working on things electrical and electronic, I'd never seen it... until today. Wrapping a blown fuse in tinfoil is not a safe thing to do. So what if you want to get your piece of equipment working. Are you really prepared to risk setting your house on fire in the process?
This was the plug for a netbook PC's power supply. I was asked to check to see if the screen was fixable. It wasn't, it needed a replacement. You could tell this without even switching it on. The power supply's output lead looked as if it had a hard time too. I was about to plug the power supply in to the mains and check it over, when I spotted the tinfoil. The joke was, perhaps fortunately, that there was nothing wrong with the fuse. I suspect the damaged lead had stopped the thing working, and some person had assumed it will be the fuse.
Just in case it's not 100% clear, DO NOT EVER DO THIS!!!
Sadly, I have seen more dangerous repairs/modifications, but I'll save those stories for other days.