110 volt and will work in any indoor or outdoor lamp fixture just as long as the bulb is protected from the weather such as rain and snow.
Yes I use them in lamps as well as inside and outside light fixtures. Just as long at they are 110volt sockets for regular bulbs and not anything exotic.
Yes, these bulbs are actually designed for ceiling fans and decorative fixture.
It is not rated for an oven, but I'm sure it could be used in a refrigerator if you wanted to try it.