parsererror SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

$.ajax({
     url: 'my.php',
     type:'POST',
     dataType: 'json',
     data:{switch:9},
      error: function(data,e,f){
        alert("Error : "+e+" "+f);
        console.log(JSON.stringify(data));
      },

     success:function(data){
            if(data.length!=0){
              
            
                // getting the data from the array
                $.each(data, function(k, v) { 
                     // set the data from database to input box
                     $("input[name='fname']").val(v['fname']); 
                     $("input[name='bname']").val(v['bname']); 
                     $("input[name='address']").val(v['address']); 
                     $("input[name='phone']").val(v['phone_no']); 
                     $("input[name='website']").val(v['website']); 
                     $("input[name='ein_ss_no']").val(v['ein_ss_no']); 
                     $(".user-catagory").val(v['business_type']).change(); 
                });
            }
            } // End of success function of ajax 1 form

  });

00:24:17.314 {"readyState":4,"responseText":"<!DOCTYPE html>n<html>n<head>n<meta charset="UTF-8">n<meta name="viewport" content="width=device-width, initial-scale=1.0"><!-- title -->n<title></title><!-- css link -->n<link rel="stylesheet" type="text/css" href="web_assets/css/bootstrap.css">n<link rel="stylesheet" type="text/css" href="web_assets/css/custom.css"><script type="text/javascript" src="assets/js/jquery.min.js"></script>n                n        <script type="text/javascript" src="assets/js/bootstrap.min3.js"></script>n        <link rel='stylesheet' href='ASLibrary/css/style3.css' type='text/css' media='all' />n               n        <script type="text/javascript" src="assets/js/respond.min.js"></script>n        <script type="text/javascript">n            var $_lang = {"email":"Email","login":"Login","useame":"Useame","password":"Password","your_email":"Your Email","login_with":"Login With[…]1 add_profile.js:10:9