yes. there is a theory that people who did not accomplish their destiny stay on earth until they have finished it. My mom has actually walked through a ghost before. I'll tell you the story in the comments!
No: It is written: Ecclesiastes 9:5 For the living know that they shall die: but the dead know not any thing, neither have they any more a reward; for the memory of them is forgotten. Isaiah 26:14 They are dead, they shall not live, they are deceased, they shall not rise: therefore hast thou visited them, and made all their memory perish. Hebrews 9:27 And as it os appointed unto man once to die, but after this the judgment.