Back when there was only one type of tail/stop light bulb to deal with (1157) that fit practically every car on the road, U-Haul sold those bulbs as a quick way to hook up trailer lights on their rental equipment. They also had female bullet connectors with sharp points that could be squeezed over wires with a pair of pliers to tap into a wire harness.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!