The only things that aren’t bound by gravity are massless. Massless things always have to be moving at the speed of light. So really the question is, what direction would the ghost shoot off to? Momentum would have to be preserved, so it’d be the opposite direction of where the corpse drops. Or maybe the corpse just move a teensy bit to the opposite direction of the ghost?

Note: this assumes Newtonian or at least semi classical physics. In general relativity, there is no such thing as being unbound by gravity.