Ambient Script CS0163

Hi, i am making a slender game but i got this error,

Assets/Slender 1/AmbientScript.cs(43,25): error CS0163: Control cannot fall through from one case label to another

here is the script

 using UnityEngine;
 
 public class AmbientScript : MonoBehaviour
 {
     public int timer = 100;
     public Transform rotateme;
     public AudioClip fs1;
     public AudioClip fs2;
     public AudioClip fs3;
     public AudioClip fs4;
     public AudioClip fs5;
     public AudioClip fs6;
     public AudioClip fs7;
     public AudioClip fs8;
     public AudioClip fs9;
     public AudioClip fs10;
     public AudioClip fs11;
     public PlayerScript view;
     public AudioSource wind;
     public IntroScript intro;
     public LoseScript loser;
     
     private void Start()
     {
         this.rotateme.Rotate(new Vector3(0.0f, Random.value * 360f, 0.0f));
     }
     
     private void Update()
     {
         if (this.intro.gamestarted && this.loser.timeleft == 0 && (!this.view.mh || this.intro.timer >= 1600 && this.view.mh) || this.loser.timeleft > 250 && this.loser.timeleft < 900 && this.view.pages >= 8)
         {
             this.wind.volume = 1f;
             --this.timer;
             if (this.timer > 0)
                 return;
             this.timer = (int) ((double) Random.value * 500.0) + 100;
             switch (this.intro.timer >= 1700 ? (int) ((double) Random.value * 9.0) + 1 : (int) ((double) Random.value * 8.0) + 1)
             {
             case 1:
             case 2:
                 if (!this.view.lost && !this.view.daytime || this.view.lost && this.view.daytime)
                 {
                     AudioSource.PlayClipAtPoint(this.fs1, this.transform.position, 1f);
                     break;
                 }
                 else
                 {
                     AudioSource.PlayClipAtPoint(this.fs8, this.transform.position, 1f);
                     break;
                 }
             case 3:
             case 4:
                 if (!this.view.lost && !this.view.daytime || this.view.lost && this.view.daytime)
                 {
                     AudioSource.PlayClipAtPoint(this.fs2, this.transform.position, 1f);
                     break;
                 }
                 else
                 {
                     AudioSource.PlayClipAtPoint(this.fs9, this.transform.position, 1f);
                     break;
                 }
             case 5:
             case 6:
                 if (!this.view.lost && !this.view.daytime || this.view.lost && this.view.daytime)
                 {
                     AudioSource.PlayClipAtPoint(this.fs3, this.transform.position, 1f);
                     break;
                 }
                 else
                 {
                     AudioSource.PlayClipAtPoint(this.fs10, this.transform.position, 1f);
                     break;
                 }
             case 7:
             case 8:
                 if (!this.view.lost && !this.view.daytime || this.view.lost && this.view.daytime)
                 {
                     AudioSource.PlayClipAtPoint(this.fs4, this.transform.position, 1f);
                     break;
                 }
                 else
                 {
                     AudioSource.PlayClipAtPoint(this.fs11, this.transform.position, 1f);
                     break;
                 }
             case 9:
                 switch ((int) ((double) Random.value * 3.0) + 1)
                 {
                 case 1:
                     AudioSource.PlayClipAtPoint(this.fs5, this.transform.position, 1f);
                     break;
                 case 2:
                     AudioSource.PlayClipAtPoint(this.fs6, this.transform.position, 1f);
                     break;
                 case 3:
                     AudioSource.PlayClipAtPoint(this.fs7, this.transform.position, 1f);
                     break;
                 }
             }
             this.rotateme.Rotate(new Vector3(0.0f, Random.value * 360f, 0.0f));
         }
         else
             this.wind.volume = 0.0f;
     }
 }

Can someone help me please?