The following is from the Hampshire Constabulary website Seasonal Advice page.
At the bottom of this page and on the Hampshire Constabulary website you will find two posters. One can be used by shop keepers to restrict the sale of eggs and flour to those under age, and the other can be printed out by homeowners to restrict "Trick or Treat" calls.
If you don’t know who is calling at your door, you don’t have to answer it.
Look through a spyhole or window before opening the door if you’re unsure, and have your door chain in place if you do answer. If you feel threatened in your home, call 999.
If you don’t want trick or treaters to knock at your door, you can put up a ‘no trick or treaters’ sign and close your curtains.
If you are part of a Neighbourhood Watch scheme, let your coordinator know that you will be on your own at Halloween. As a coordinator, you should identify people in your scheme that may be vulnerable and offer them reassurance.
If your child is going out trick or treating, make sure they:
Below you will find copies of the posters available from the Hampshire Constabulary website Seasonal Advice page.