2D Character Switch Systsem (Same Location)

Make all three character sprites a child to a single empty gameobject so that their positions and what not all remain the same. Then enable/disable their renderers.

So I'm pretty new to scripting but I'll try an example.

 #pragma strict
 
 var character1 : Renderer; // Your first character
 var character2 : Renderer; // Your second character
 var character3 : Renderer; // your third character
 
 var activechar = 0; // when 0 active character is char1, when 1 active character is char2, etc.
 
 function Start()
 {
 activechar = 0;
 character1.enabled = true;
 character2.enabled = false;
 character3.enabled = false;
 }
 function Update()
 {
 if(Input.GetKeyDown(KeyCode.E))//if they press E the active char is switched
 {
 activechar++;
   if(activechar >2)
    activechar = 0;  // makes sure it cycles through your 3 characters
 }
 
 IsActive(); //calls the IsActive function to see which sprite is enabled
 
 }
 
 function IsActive()
 {
 if(activechar==0) //shows only char 1
 {
 character1.enabled = true;  
 character2.enabled = false;
 character3.enabled = false;
 }
 if(activechar == 1) //shows only char 2
 {
 character1.enabled = false;  
 character2.enabled = true;
 character3.enabled = false;
 }
 if(activechar == 2) //shows only char 3
 {
 character1.enabled = false;  
 character2.enabled = false;
 character3.enabled = true;
 }
 }

Drag your 3 sprites onto the renderer areas in your empty gameobject in the inspector thing to match the char1/char2/char3. There might be a better way to do this, but I'm pretty new to Unity so I'm still learning. Hope this works!