you were getting ready for bed. you turned off the lights and layed down. your eyes closes and you started falling asleep.

suddenly you heard a soft voice, almost like a whisper "you think you're alone, but you're not."

your eyes open immediately but you don't see anyone, you look around your whole room but you don't see a single person, when you hear the voice again "I'm here, yeah"

you again don't see anyone, is it a ghost?