I'd always been led to believe that "witches" held satanic rituals and sacrificed kittens on October 31st. However, Wiccans do not, as a whole, believe in Satan, and most Wiccans I know have the good sense not to worship things that they don't think are there. Also, according to my sociology texts and Snopes, there is little evidence to suggest that cat sacrifices are a thing. The reason shelters don't give out black cats in October is the same that pet stores don't sell ducks and bunnies at Easter - because people will buy them as holiday decoration and then ditch them.
Anyway, I thought I'd tell you a thing or two about some of the things I've been learning from my Wiccan friends.
So first of all, Wiccans celebrate Samhain on October 31st, not Halloween, which is largely a secular holiday. Although Samhain is pronounced "Saween" (or close to it), the words Samhain and Halloween are not etymologically related. Samhain probably evolved from a word of Celtic origin, a word meaning summer's end. Why it's not pronounced anything like Samhain I'm not sure. Probably for the same reason that Greenwich is not pronounced Greenwich.
Samhain was a harvest festival, nothing sinister there. It was believed that, since so many plants and animals die at this time of year, the veil between the world of the living and the world of the dead became thin, what with all the traffic, and so people used the day to celebrate and sort of commune with the dead. This is nowhere near as creepy as our communing with our dead loved ones by pumping them full of formaldehyde and covering them with makeup so that they don't look dead.
The trappings of Samhain are also nowhere near as creepy as the trappings of Halloween. While there are often lots of skulls and bones around, they're not there to scare people or freak people out, but just as a memento mori, if you will. Lots of cultures do this. It's interesting that mainstream American culture sees bones as bad and scary while so many other cultures see them as a natural part of life.