Here is the classic light up bulb. Hold am ordinary looking light bulb in your hand. Upon the magicians command it will light up bright. The magician can turn it on or off just by holding in their hand. No secret buttons. As you can then hand the bulb to the audience. They will examine it fully but will not be able to preproduce the effect. Use for jokes or pranks.
Easy to do for kids as it works automatically once you know the secret of the magic light bulb.