Research shows that people who die make their presence known in many ways. These include:

(1) Sensing their presence
(2) Hearing their voice
(3) Feeling their touch
(4) Smelling them
(5) Seeing them as if they were real
(6) Seeing a flat vision of them like a photo
(7) Experiencing one of these while half-asleep
(8) Having a visit in a dream - but the dream is unusually vivid and you do not forget it like a normal dream
(9) Having an out-of-body experience and meeting them
(10) Receiving a telephone call from the person who died (two-way conversations have been reported)
(11) Experiencing electrical appliances such as lights, TVs, and radios going on and off
(12) Receiving a symbolic message, sign, meaningful coincidence, or synchronicity. Read more.