Adding prefab ParticleSystem to a GameObject?

Hey, Id like to add a already premade ParticleSystem to my Main Character, because I have multiple Characters with different particles. I dont want to make a prefab for every single Character. My approach would have been this:

 public GameObject[] obj;

 // Use this for initialization
 void Start () {
     if (!PlayerPrefs.HasKey("CharSelected"))
     {
         PlayerPrefs.SetInt("CharSelected", 1);
     }
     int pchar = PlayerPrefs.GetInt("CharSelected");

     switch (pchar)
     {
         case 0:
             Destroy(this.gameObject.GetComponent<ParticleSystem>());
             this.gameObject.AddComponent(obj[0].GetComponent<ParticleSystem>());
     }
 }

But AddComponent only lets me add a Type of a Component, not a premade one. How could I solve this?