I would definitely haunt some place, but i think I would use it for good. I was mugged really badly about 9 years ago, and had my head split open. It's kind of blurry, but I remember being asked if I wanted to quit or continue, meaning basically, here is a choice where you can live or die. I said that I didn't know, and passed out. I only had a split second to think about it. Well, turns out that I didn't die, and quite probably should have. I was bleeding internally in my brain, but for some reason it stopped. I came to long enough to make it to a friend's house and go to the hospital. My skull could have shattered but didn't. I could have had permanent brain damage, but lucked out.
Had I died, I would have returned to the guy's place that did this. I assume that he mugged me for some quick money for drugs. After years of anger, I have actually prayed for him. He is in far worse place than i ever was. And I would continue to haunt him until he saw the extreme damage to people's lives he was causing. I would haunt him until he wanted to quit the drugs and turn for help, and figure out why he needed drugs in the first place. But I think after I was done, I would also be sure that I saw him one last time, told him that I had already forgiven him long ago, and that he is loved by God very much, right now. I would leave him when he really understood that he was lovable, that he was a worthy life. I suspect that many people with addiction are actually full of self-loathing.
I would also go and visit friends and family from time to time.
My father passed about 2 years ago, and shortly after his death, I would be at home, and suddenly sense someone there, sense his spirit, and even smell is cologne. This happened very strongly 3 different times. Recently, i was dreaming that I was lying in bed, and i looked over and saw my dad. He said, "Hi. I just thought I would stop by and say hi." I said, "It's so good to see you!" Then, I woke up, and was like, "whoa. I think my dad just visited me in my dreams."
I would probably also want to haunt some hotel, and say something like, "Who stole my uuuuuuuvula?"