Here is another snippet

http://archives.quillandparchment.com/Dec2005/Soul.html

The practice of 'trick or treating' was thought by some to have it's origins on All Soul's Day, not All Hallow's Eve. On this day, children and street urchins would go begging treats of people in the neighborhood in exchange for praying for their loved ones in purgatory. If they were refused, they would often 'visit mischief' on the household. Thus the song made popular by Peter, Paul and Mary (but with much older origins):

Hey ho, nobody home,
Meat nor drink nor money have I none,
Yet shall we be merry,
Hey ho, nobody home.

Soul, a soul, a soul cake,
Please, good missus, a soul cake.
An apple, a pear, a plum, a cherry,
Any good thing to make us all merry,
One for Peter, two for Paul,
Three for Him who made us all.

God bless the master of this house, and the mistress also,
And all the little children that round your table grow,
The cattle in your stable and the dog by your front door,
And all that dwell within your gates, we wish you ten times more.

Soul, a soul, a soul cake,
Please, good missus, a soul cake.
An apple, a pear, a plum, a cherry,
Any good thing to make us all merry,
One for Peter, two for Paul,
Three for Him who made us all.

Go down into the cellar and see what you can find.
If the barrels are not empty, we hope you will be kind.
We hope you will be kind with your apple and strawber’
For we'll come no more a-soulin' till this time next year.

Soul, a soul, a soul cake,
Please good missus a soul cake.
An apple, a pear, a plum, a cherry,
Any good thing to make us all merry,
One for Peter, two for Paul,
Three for Him who made us all.

The streets are very dirty, my shoes are very thin.
I have a little pocket to put a penny in.
If you haven't got a penny, a ha'penny will do.
If you haven't got a ha'penny then God bless you.

Soul, a soul, a soul cake,
Please, good missus, a soul cake.
An apple, a pear, a plum, a cherry,
Any good thing to make us all merry,
One for Peter, two for Paul,
Three for Him who made us all