These personally I find quite fascinating. There are a number of anecdotal accounts of these, one in particular stands out, which I will relate later.

This type of spirit allegedly appears only a few times, often one once and seems to have a purpose of passing on some form of information. One interpretation is to say goodbye or to tell someone that they have passed on. Usually these spirits only appear to someone who is a close friend or relative, sometimes one at a time sometimes to a gathered group.

Some accounts suggest that people in different parts of the country have received a visitation at exactly the same time.

People who have received such a visitation describe a feeling of wellbeing and a renewed belief in the hereafter and of feeling comforted.

Now on to an account that I have seen written down, it is singular in that the account cites the experiences of several individuals who are all convinced of what they saw separately, but which taken together form an interesting story. I cannot say that I believe it, but here it is.

It is 1917, a train pulls into a country station and from out of the mist walks a smartly dressed officer, whom the porter collecting tickets recognises immediately as the local lord of the manor. He greets him respectfully and unusually does not get a reply, the officer walks on as if he has not seen the porter. Outside the station he is seen by others who describe him as fixed on a task, he is offered a lift in a taxi, but turns away and walks purposely up the road in the direction of his house. He is seen by many on the walk, but stops to speak to none. He is seen walking through the garden by his gardeners ho all touch their caps and say good morning, but unusually get no reply. He is next seen in the house by a maid, who summons the butler to attend. The butler sees his master at the top of the stairs and follows him to his mistresses room. When he enters the room he sees his master talking to the mistress and at that moment he vaporises.

A day later a telegram arrives telling his family that he has been killed in action, strangely at around the time that he was seen.

I have read accounts of this story several times, although I cannot remember where, but it certainly makes you stop and think. The sceptics view is that people were mistaken or got the dates mixed up, that this is a bit of charming folk law. It nevertheless demonstrates the messenger spirit, you can find many other accounts of this type in books or on the web