69 valiant electrical gremlin turn signal and license plate light

using the test light as instructed; there is power to the socket. (license plate bulb) i tested it and the light comes on but when i put bulb in, nothing. brand new bulb pack, tried both bulbs and nothing. i even removed the part you have pictured and tested further up, there was light there too just no bulb lighting. I sanded out the hole again even though i was getting the test light to come on when touching. still nothing.license plate light holder.jpg ligh bulb.jpg