According to Osho, sightings—like a figure resembling Milarepa—should be met with relaxed awareness. Neither believe nor deny; watch. Slow your breath, feel your body, and let fear pass. If the presence feels loving, receive its blessing; if it provokes fear, center in witnessing and it dissolves as a play of mind-energy.
If you see a ghost, stay calm, just watch and breathe, and it will either bless you or fade away.