The saying that the fact that ghosts make contact validates afterlife is not scientific. There is no documented case with sufficiency to prove such a connection although plenty of anecdotal cases and historical records mention this connection. Claims are based on the personal experiences and not verifiable evidence that is reached up to the scientific standards. It involves extraordinary claims but does not have extraordinary evidence.
Documented sightings of ghosts are there in historical records. Nonetheless, these descriptions are not scientifically controlled, and they are also subject to misinterpreting or falsity. Documentation also fails when put to serious test. There is no objective evidence of personal belief in an afterlife.
Ghostly phenomena have been studied hard by scientists since the 1900s. The results are clear that there is no convincing evidence that there is an afterlife. There are assumed occurrences that are due to a natural reason, psychological forces or camouflage. and the evidence developed by any investigation has never been conclusive and reproducible.
Stories of supernatural interactions by individuals are convincing to people. Nevertheless, human senses are not reliable. Other things such as grief, anticipation, or even loss of senses can easily explain most of the experiences. The emotional appeals do not make the supernatural causation sound. These are personalized readings.
Apparitions are also commonly seen as spiritualist evidence, and captured during encounters. However such interpretations depend on faith-based structures which are not falsifiable. These yield individual significance though not scientific tests within the reach of outside observation. The claim to prove them is universal remains a claim of philosophy.
Conclusion:
There is no documented scientific evidence of any ghostly encounter that can be verified to show life after death. Strict analysis always has a set of natural causes, psychological conditions, or the lack of evidence as the reason behind such phenomena. These encounters are subject to interpretation, although it has some personal meaning to some people. They fail to achieve the objective, repeating standard criteria necessary to scientifically support the existence of an afterlife.