I'm not a believer myself (hope nobody is offended) but my grandmother did have a story which always sent shivers down my spine. She was a very devout Catholic and did not believe in spiritualism, ghosts etc until this happened, as she felt it was against her religious beliefs.
However, one evening (this is going back around 30 years) she was at home alone early evening (around 5pm) and suddenly felt very unwell. She said she suddenly, without warning, felt freezing cold, started to shake uncontrollably and had trouble breathing. It lasted for about 10 minutes and my grandmother was very close to calling for an ambulance, but she said it then passed as quickly as it had come on and she felt perfectly normal again.
She then decided to go and get her washing in from the line in her front garden, and while she was out there, she saw a friend (lets call her Anne) who lived locally walking past on the other side of the lane (they lived in rural Ireland). She said she did think it was odd that the friend was out at gone 5pm and walking seemingly in the opposite direction of her home, towards a very windy, leafy lane that leads down to the sea. She waved and called out to her friend, and her friend turned to her, smiled and waved but didn't stop or say hello. She saw her friend's face full on, and said it was definitely her and that she looked fine, well, happy.
At around 7pm my grandad came home from work and told my grandmother that he had just seen Anne's niece outside their home and that Anne had died at around 5pm, sleeping in her favourite chair in front of the TV (she had had a heart condition). There is no way the woman my grandmother saw could be Anne, but to the day she died she maintained that it was her.