Well my friends tomorrow is 'All Hallows Eve', 'Samhain', 'Halloween', and a host of other names. It is one of the major holidays for those of us who follow most forms of paganism, or Wicca (and other Earth based, Old religions).
For the most part this is one of harvest festivals. But the other thing is that this is also (almost worldwide) a celebration of the ancestors.
Many of us will hold a 'Dumb Feast', aka 'Silent Feast' or 'Dinner for the Ancestors'. This is a meal for the honor of family members who have died. (I like to use the term crossed-over). A place is set (sometimes one place for each to be commemorated, usually one place but with pictures of all the ancestors to be honored). The dinner is made from their favorite foods, and eaten in silence. A portion of the food is put on the plate as an offering to the honored guests. Once the meal is completed then you go around the table to talk about and reminisce about the ancestors, friends, pets who have passed on. Then the plate or plates are taken outside and the food left with a prayer of thanks.
But, the other thing that sets this night apart (and makes events like the Silent Feast possible) is that the veil between our world and the world of Spirit is thinnest. And so it is much easier to make contact with the departed on this night over all others. But that also means that those spirits who aren't so nice also have an easier time to come into our world and cause a bit of problems.