For the dressing: In a small bowl, whisk together the grapefruit juice, oil, mint, zest, chile paste and salt. Set aside to let the flavors marry.
For the skewers: Preheat a grill pan set over medium-high heat. Skewer one shrimp in a "C" shape, followed by a grapefruit segment, then followed by another shrimp. Continue skewering the remaining shrimp and grapefruit segments. Sprinkle the salt evenly over the skewers and drizzle with the olive oil. Grill the skewers until cooked through and opaque, about 3 minutes per side. Spoon the dressing over the shrimp and serve.