In the below example I have created Customizing Switch button. Here I have added a Switch in activity_main.xml layout. In second step I have created backgraund.xml layout in drawable folder, here I have design switch backgraund shape. In third step I have created a new customtrack.xml layout in drawable folder.Now in next step I have added string name with in String.xml layout. In MainActivity I have used toast function. You can see below program it clearly describe you How to make Custom Switch in android.
Step(1)activity_main.xml layout-

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/backgraund"
    android:orientation="vertical">


    <Switch android:id="@+id/swtch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textOn="@string/checkedstate"
        android:textOff="@string/uncheckedstate"
        android:minWidth="25dp"
        android:layout_marginTop="29dp"
        android:layout_marginLeft="40dp"
        android:switchPadding="10dp"
        android:onClick="togglestatehandler"
        android:thumb="@drawable/backgraund"
        android:track="@drawable/customtrack"
        android:thumbTextPadding="15dp"
        android:textStyle="bold|italic"
        android:typeface="sans"/>

</LinearLayout>

Step(2)-Created a new backgraund.xml layout in drawable folder-

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:state_checked="true">
        <shape android:shape="rectangle"
            android:visible="true"
            android:dither="true"
            android:useLevel="false">

            <gradient android:startColor="#66AAFF00"
                android:endColor="#6600FF00"
                android:angle="270"/>

            <corners android:radius="15dp"/>

            <size android:width="27dp"
                android:height="37dp" />
        </shape>
    </item>

    <item android:state_checked="false">
        <shape android:shape="rectangle"
            android:visible="true"
            android:dither="true"
            android:useLevel="false">

            <gradient android:startColor="#66e133b6"
                android:endColor="#6619e4d6"
                android:angle="270"/>

            <corners android:radius="15dp"/>

            <size android:width="27dp"
                android:height="37dp" />
        </shape>
    </item>


</selector>

Step(3)-Created a new customtrack.xml layout in drawable folder-

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle"
    android:visible="true"
    android:dither="true"
    android:useLevel="false">
    <gradient android:startColor="#660000FF"
        android:endColor="#6600CCFF"
        android:angle="270"/>
    <corners android:radius="15dp"/>
    <size android:width="30dp"
        android:height="40dp" />
</shape>

Step(4)-Add string in string.xml -
    

  <resources>
       <string name="checkedstate">START</string>
        <string name="uncheckedstate">STOP</string>
      </resources>

 Step(5)-MainActivity-
 
 

public class MainActivity extends AppCompatActivity {


    Switch switchbtn;

    private Context context = this;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        switchbtn = (Switch) findViewById(R.id.swtch);
        applyStyle(switchbtn.getTextOn(), switchbtn.getTextOff());

    }


    public void applyStyle(CharSequence switchTxtOn, CharSequence switchTxtOff) {

        Spannable styleText = new SpannableString(switchTxtOn);
        StyleSpan style = new StyleSpan(Typeface.BOLD);
        styleText.setSpan(style, 0, switchTxtOn.length(), Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
        styleText.setSpan(new ForegroundColorSpan(Color.GREEN), 0, switchTxtOn.length(), Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
        switchbtn.setTextOn(styleText);

        styleText = new SpannableString(switchTxtOff);
        styleText.setSpan(style, 0, switchTxtOff.length(), Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
        styleText.setSpan(new ForegroundColorSpan(Color.RED), 0, switchTxtOff.length(), Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
        switchbtn.setTextOff(styleText);

    }

    public void togglestatehandler(View v) {
        Switch switchbtn = (Switch) v;
        boolean isChecked = switchbtn.isChecked();

        if (isChecked) {
            Toast.makeText(context, "On......", Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(context, "Off......", Toast.LENGTH_SHORT).show();
        }

    }
}