Socket namespace for a chat module
Extract the common logic to a function,
where the varying parts are parameters.
Unless I'm missing something, this looks trivially easy to do:

function setup_namespace(org_id) {
    var nsp = io.of('/nsp_bucket_' + org_id);
    nsp.on('connection', function(socket){
        console.log('someone connected to namespace bucket ' + org_id);

        socket.on('addEmp', function(login_org_id, login_emp_id, login_emp_name){ 
            console.log('addEmp - Org_Id : ' + login_org_id);
            console.log('addEmp - Emp_Id : ' + login_emp_id);
            console.log('addEmp - Emp_Name : ' + login_emp_name);     
        });

        socket.on('disconnect', function() { 
            console.log('Someone disconnected from namespace bucket ' + org_id);
        });
    });
    return nsp;
}

var nsp_1005 = setup_namespace(1005);
var nsp_1010 = setup_namespace(1010);


If you don't need to retain those variables,
then you could remove the variables and just leave the calls:

setup_namespace(1005);
setup_namespace(1010);