Is the celebration of Halloween practicing witchcraft?
Definitely not. Halloween has become and excuse to dress up and get free candy. there is nothing wrong or blasphemous about celebrating Halloween.
Actually it is in a sense just as most of the "hallmark" holidays were once major pagan holidays. Halloween, or known as it's true Celtic name of Samhain (pronounced (SOW-wen) is the first holiday of the major eight in the year often called the 'Wheel of the Year'.
This sacred holiday is not about devils, costumes and midnight children boilings like Hollywood would like you to believe. It is a solemn holiday where witches hold celebrations to honor the dead. I can't speak for all witches, but I fast and hold a candlelight vigil for those who I've lost in the past year. This year I add to my list my dear friend, who recently lost her battle to breast cancer. I give thanks to those that have died for my freedom, for our country, family and friends. This holiday also marks the death of the witches Lord, the Goddess's consort.
One of the many thoughts about Samhain and the history of dressing up was to scare away spirits. Because this is a night in honor of the dead, and because it is believed that the veil that seperates the worlds of the living and the dead are at its thinnest this night - people lit pumpkins and carved gourds to keep spirits away.
In Mexico, the dead are celebrated and honored also, not feared and shunned. It is a sacred holiday, one not meant for dressing up and candy overdosing. That doesn't mean that witches won't celebrate with the rest of you and have some fun - but most likely not on October 31st.
To learn more about witches' holidays please read this: http://www.geocities.com/SoHo/Cafe/1614/Celtwicc/Wicca/Wicca04.htm