Soak skewers in warm water for 20 min. Preheat barbecue to medium. In a large bowl, stir lemon juice, paprika, oregano and salt together. Pat shrimp dry. Add to lemon-juice mixture. Toss to coat. Let stand for 15 min. Meanwhile, cut chorizo into 1-in. pieces. Carefully thread shrimp and chorizo alternately on skewers. Barbecue until shrimp are pink and chorizo is warm, 2 to 3 min per side.