I do not see why not? It is really up to you. I am a practicing pagan witch for several years now and I dress up for Halloween. It is a fun holiday. The only difference is in the evening I let my family finish setting up decorations while I perform a ritual honoring the dead and my gods. For me it is both my favorite fun holiday and a very spiritual holiday.
Halloween is not a christian holiday. It is called sambaing. I say you can where what you want. I am Wicca. If you are doing a ceremony or ritual then maybe you should consider something more traditional. Blessed Be
I'm not sure really cause i don't know much about it. My friend is one and says that the religion focuses on mother nature and everything around it. I don't really EEO it as a problem since Wicca seems to be a peaceful religion with many restraints.
I'm not really sure about the restraints part, maybe you're a vegetarian or something like that but i still don't see a problem with it.
Add:
Samhain is NOT Halloween. Halloween is a time to trick or treat and scare the crap out of each other. Samhain is about honoring our deceased. It only happens on the same day. Dia DE Laos Muertos is also celebrated that day but they don't claim it IS Halloween.
Of course. Halloween has nothing to do with Wicca, and the popular celebration of it (candy, costumes), has nothing to do with any religion. It's secular.