Do I believe in them? YES I do. I have had personal experiences myself to know that I would not have made it through had it not been for my guardian angel protecting me. I strongly believe that there are "spirits" both bad and good that are watching us.
My friend Pam said today that she got a call at 3am..."Mom?...I'm alright (sirens in background) I feel asleep at the wheel and flipped my car 5x. I am okay just a few scratches on my face." Her son is studying to be a preacher and we all know that God has bigger things planned for him. I wasn't there, but I can just imagine his guardian angel or Jesus took the wheel and led this boy to safety.
My other friend was asking me if I believed in demons. I said yes. She told me about how she thought she was sleeping but it felt too real to be a dream. She woke up out of breathe because she felt a hand over her mouth. She wasn't quite sure if was real or not and when she was awake...her breathing was still labored. She just moved to a new apartment building. I told her that she needs to cleanse or bless the apartment. In catholic faith we also use holy water to go from room to room and say a prayer to Michael, the archangel. She might have a lingering spirit.
I know some people are skeptics and that is fine. But I am a huge "Ghost Hunters" fan and know that there are just too many coincidences for spirits to not exist. I also watched my mother who was in a drug induced state (between earth and another realm) call out in her hospital room, "Come on Baby" as her first great-grandbaby was being born in the maternity floor of that hospital. It was like she was there with my niece, even though she never moved out of her bed.
I know I have angels watching over me. I know their names too!