A lamp in your dream or vision tells you about guidance, hope, inspiration, enlightenment and confirmation in life. Another explanation is about insights, solutions, finding the way in life, follow your feelings and listen to your true self. You see the opportunities, you yourself are the light in the situation or possibility.
You have the knowledge, wisdom, skills to be successful. An alternative explanation is the realization that the answers you seek, the solutions you seek are already in your head, yourself; you just have to turn on the lamp.
Dreams or visions in which the lamps do not come on tell you something about yourself and the way you look at things right now. If you do not see it, you cannot reach it, the unknown, that which is not yet tangible.
The shadow side of yourself and / or the situation you are in. Things are not clear yet, you want insight, support, help or answers that you cannot find.
As it were you deprive yourself of light in the darkness - solutions and possibilities do not come to you provided you give yourself permission to turn on the light.