Hi. 

Is it possible to be a spooky ghostie in this? 

A temporal body stuck between this world and the next allowing this person to affect the physical world and the after world but only in limited ways due to the conflict of being stuck between both worlds? This character could serve by communicating with the dead or scouting ahead for potential dangers, tracking people unseen, etc...

A potential explanation of this type of ghost could be necromancy mistake or a seance gone wrong, maybe.

It could be super interesting, maybe. But it is up to you guys, I guess.