Haunt some of the powerful but evil people in the world and see what I can change. Let’s see how effective a dictator like Kim Jong Il can be with a ghost all up in their business.

If I have poltergeist abilities then I suppose just straight up assassinating people would be possible. After all, if you can shove a book off the shelf or flip a light switch then breaking a few tiny blood vessels in someone’s brain to give them a stroke is going to be easy. Not that killing other people would be easy, but maybe as a ghost I’d have a different perspective on death.

Complain, mostly.

Assuming I can interact with the physocal physical world, prove ghosts are real

Edit: I can’t spell

Ruin the technology of my enemies

Get together with my floating friends and have a floating party fun.

Since I presumably can’t play video games anymore without hands, I’d probably watch others play games over their shoulder and judge them for not playing the same way I would. If they made a really bad misplay I’d probably turn into a poltergeist and start throwing stuff

Finally get through my r adding backlog. With nothing to distract me and no need to eat or sleep, I might actually finish it in a few decades.