Sram Red squeaking

[Luca79]

I have this annoying squeaking/vibration noise coming from the left shifter/brake lever of my Sram Red.
It appears at every asphalt roughness the bike passes on.

The noise seems to go away if I hold that area firmly with my left hand.

Any suggestions on how to fix it?

Thank you!

[speedwobbles]

Sometimes dry lube on the little black plastic bit on the backside of the brake lever quiets that down. Also squirt a little into the pivots for the brake lever and the shift paddle.