The most frequent question about lightning protection is, "Since I am installing a copper item on my roof does that increase my chances of getting hit by lightning?". The best short answer I can give is, possibly. Yes, you are adding some height, which changes things, but one item may not be too critical. If all you are doing is adding a little extra height to your home and, NOT grounding it, then it does not matter too much if the finial is copper, wood, fiberglass, etc;. Everything changes if you decide to ground an item and unless it is part of an overall lightning protection system you may be inviting trouble. The best way to deal with lightning protection is to contact the Lightning Protection Institute and find a qualified installer in your area. A properly designed and installed system will provide the correct protection for the home. For more information follow the link to the Lightning Protection Institute.