My app crashes because I declared a checkbox equal to a checkbox

When I open this activity my app crashes and says that it is due to this line of code:

private CheckBox chkWeekly = (CheckBox)findViewById(R.id.alarm_details_repeat_weekly);

The layout for alarm_details_repeat_weekly is right here:

<CheckBox
        android:id="@+id/alarm_details_repeat_wednesday"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/alarm_details_label_wednesday"
        android:layout_alignBottom="@+id/alarm_details_label_wednesday"
        android:layout_alignParentRight="true"
        android:checked="true" />