Scratches, words written on walls, Electronic Voice Phenomenon (EVP's), white noise, disembodied voices, movement, tapping, gut reactions, possession. Spirits speak to the living in many strange, and unsettling, ways.
Real or fake, doesn't matter. If it's fake, it's fun to pretend but if it isn't.... well....
Have I missed any methods by which the dead speak to the living. Real or Fake? Let me know in the comments.