In case if you wonder "Is it possible to communicate with the dead people?", this is a good information for you. In science they call it "After-death communication
are communications that either are believed to or appear to have been received from a person who has died.
Precise definitions of ADCs vary. According to Bill and Judith Guggenheim, an ADC occurs when a person is "contacted directly and spontaneously by a deceased family member or friend, without the use of psychics, mediums, rituals, or devices of any kind" (Guggenheim 2005).
Psychologist Allan Botkin uses the term induced after-death communication IADC (Botkin 2005) for his practice of inducing perceived reconnections with key people for grief therapy.Prevalence of ADCs
"It's estimated that 50-100 million Americans - 20-40% of the population of the United States - have had one or more ADC experiences" (Guggenheim 2005).References
Guggenheim, Bill and Judith (2005), After-Death Communication (ADC): Hello From Heaven! by Bill and Judy Guggenheim
Botkin, Allan (2005), Induced ADC's for Grief Therapy" http://en.wikipedia.org/wiki/After-death_communication
I hope to learn more about it.