I would tell my sister before I die very specific things I would do as a ghost, then not do them, so she begins to doubt that ghosts are real. Even though I would have also proved my own scepticism wrong by being a ghost, it would be funny to change her thinking :)

My job I guess.. I work as a set designer and decorator for a large haunted house attraction. So ill just continue doing what I do.. move stuff around.

I would hide every matching sock and glove they have, so they appear in random places.

They'll be like "What is pink sock doing in the freezer?!?"

[Evil Laugh]

Whisper into their Alexa devices, so that weird stuff keeps getting delivered by Amazon.

I would turn every piece of clothing they had inside out.

Every day.

I would haunt telemarketers while they are sleeping to ask about their extended warranty.

That characters in books written by man and that have plunged the world's nations into war for millennia are in fact fictitious.

I'll probably sound like a conspiracy theorist, but I truly believe that the existence of extraterrestial life is being hid from us. Do I think we have been visited/contacted? Maybe, maybe not. I have no proof, but it just makes sense considering how things are hidden by governments daily.

Not really a weird belief (at least not to me). I believe that friendships you make online through videogames are often more real than some friendships made in real life.

Example: I made a friend playing an online game. The friendship she and I share has been going strong for more than 10 years. We've never met IRL (only videochat a few times to say Happy Birthday or Merry Christmas Etc).
All of my long term friends IRL, I have lost contact with or they've just stopped communicating. The one that hurts is a friend from highschool who was at my wedding, Ghosted me completely after sending an invite, then their partner rescinded it.

Online Friendships are valid and sometimes more so than people you know IRL.