unity – Switch/Case on a large number of cases?

I’ve written a number of cases for this switch but I want them to have different rates of occurences. For example I thought of changing the random range from (0,3) to (0,101) to get numbers from 0 to 100 to implement a system like percentage (%). The problem is, is there a way to have cases to have ranges between two numbers? I mean like we say;

case 0:
case 1: 


is there a way to say

case (0,25):
case (25,50): 

Here is my initial code btw:

  public void RandomMove()
        int behaviour = Random.Range(0,3);
            //0: move left, 1: stop, 2: move right //
            case 0: rb.velocity = new Vector2(-moveSpeed, rb.velocity.y);
            movingRight = false;
            case 1: rb.velocity = new Vector2(0f, 0f);
            case 2: rb.velocity = new Vector2(moveSpeed, rb.velocity.y);
             movingRight = true;