I am stuck in the middle to be honest.
I do not like certain costume choices like witches, representations of the devil, vampires, something totally explicit, etc. (Not sure if I exactly care for the Jesus costumes, either since that may be more like a mockery to some) especially when there are much more light hearted choices like cowboys, princesses, butterflies, etc.
Halloween has been made a traditonally dark holiday mostly because of the belief of thinning spiritual barriers that allow "things" to come through into our plane more easily. There are probably higher instances of dangerous things like ouija board use, magic and spell usage, human and animal sacrifices, etc. Really, there is a lot of occult stuff going on. It is no joke!
However, Halloween is more of what the pagans celebrated. However, the trick or treating thing became more of an American tradition. Same with jack o lanterns from pumpkins. I think it was something else before like turnips. However they served a similar purpose to keep evil spirits away.
Before, it was actually All Saint's Day often celebrated November 1st. This was to feast and honor the saints whom are no longer with us.
I see churches using their space for a "light night" to provide a more safe and controlled environment in a well lit church. Although, the idea in itself isn't bad, sometimes these churches do not even mention Jesus.
For a few years my husband and I use it as outreach. We usually buy a bulk order of fun tracts that appeal to kids and are also good for adults that do not know Jesus. We get small ziploc bags, put a tract in each one, and then some candy. We figure if kids come to our door, we might as well use it to spread the gospel some how. Plus, parents with little ones usually love the ziploc bag idea so their toddler can't automaticaly put the candy in their mouth.