Motorbike flashing brake light

Hi lads, I am trying to control lightbulb 12V via arduino, I got TIP120 transistor, but all the schematics shows that I have to connect TIP120 emitter to the ground and collector through bulb to 12V... But it is for motorbike and I need to switch 12V to a bulb, not ground, because the whole frame is 0V. Just wondering if anyone have experience with it? Basically I want to make flashing brake light and want to use +12V from brake relay to power arduino and switch the bulb (only "setup" section on the sketch 5x flash then stays on) and it is impossible to switch 0V of the bulb, because it is always connected to the frame...

Your question is not very clear....please clarify what you wanna do....

Your bulbs are connected to the chassis, which is ground, so you need to switch the +side of the bulbs, right?

high side fet switch circuit should be a good choice.

google "high side fet switch circuit".