Test Class Code Coverage Issue : System.QueryException

My Apex class is

Class1:

      Public class myclass{
             //some code
           public void save(){
                invoice_policy__c inp=[select net__c,Internal_alerts__c,Send_Email__c,Email_Alerts__c,Send_To__c from invoice_policy__c where id=:selectin]; //getting error here
         if(inp.Internal_alerts__c == true){
             //some code

           }
       }
string Selectin;
Public string getSelectin(){return Selectin;}
public void setSelectin(string selectin){this.selectin = Selectin;}

       public list<selectoption> getselectname()
      {
          list<selectoption> option = new list<selectoption>();  

         for(Invoice_Policy__c invoice : [select id,name,Policy_Status__c from Invoice_Policy__c where Policy_Status__c='Active'] )  
          {       

             option.add(new selectoption(invoice.Id,invoice.name));
              system.debug('invocenameee'+invoice.Id);  
              }
            return option;     
     } 
   }

My test class is

invoice_policy__c ip = new invoice_policy__c(name='TestPolicy',net__c='3',Policy_Status__c='Active',send_to__c='[email protected]',Email_Alerts__c='Before',Internal_Alerts__c =true);
        ip.send_email__c='2';
        insert ip;
        system.debug('testttt'+ip);

         myclass ic = new myclass();
        ic.getselectin();
        ic.setselectin('a0Wi0000000NMqbEAG');
        ic.save();

Getting error as System.QueryException List has no rows for assignment to SObject Help on this pls