I know about ghosts. I've seen them many times (and talked to others to try and get them to pass on).
In response to your problem though: Reiki (good healing energy)! A LOT OF IT! Put some of it into a necklace and charge it once a week, use it around the spot that you hear footsteps or feel bad energy, and for extra protection use it where you sleep. Also, use sage smudge sticks and use it on ALL openings doors, windows, sliding glass doors, everywhere. Try a few protection spells. If you friend doesn't believe in magick, give them a necklace with a protection spell: http://www.spellsofmagic.com/spells/luck_spells/good_luck_spells/13959/page.html
that spell works great as a protection spell.
I hope this helps. Good luck with your ghost.