Are there such things as Ghosts?

Demons, which are fallen angels can certainly change their appearance (as familiar spirits) and actually mimic, sound like the person they are impersonating. They do have this ability to deceive and make people think they are actually the spirit of that person, the ghost of that person communicating to them.

Angels have powers beyond what we have, fallen and un-fallen. The Bible teaches us that Satan can still transform himself into an angel of light, as do his ministers.

Lets not be so naive as to say I knew it was an angel because he had a halo over its head ( he, she spoke beautiful things to me); Or I knew it was a devil because it had a tail and horns (and it made me sacred).

The bible explicitly tells us not to try and communicate with the dead (called necromancy; this is trafficking in the occult) because we are not contacting the person who passed on. The Lord is trying to protect people from further harm, especially in their vulnerable state. After death there is still life but there are only two locations to go to. Neither one of them offers the opportunity for the departed to be visiting us and we should understand this so that we do not get misled.