How do I solve this error? Could anyone help me

Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.

Select
CASE
    WHEN 
		(SELECT subject_type FROM cdbwf_task
		WHERE cdbwf_task.cdb_process_id in (SELECT cdb_process_id
					FROM   cdbwf_process
					WHERE  EXISTS (SELECT cdb_process_id 
									FROM   cdbecm_briefcase2ec_v 
									WHERE  cdbwf_process.cdb_process_id = cdbecm_briefcase2ec_v.cdb_process_id)) AND status = 10) = 'Person' 
		THEN 
			(select personalnummer 
			 from angestellter 
			 where personalnummer in (
					   SELECT subject_id FROM cdbwf_task
					   WHERE cdbwf_task.cdb_process_id in (SELECT cdb_process_id
							FROM   cdbwf_process
							WHERE  EXISTS (SELECT cdb_process_id 
											FROM   cdbecm_briefcase2ec_v 
											WHERE  cdbwf_process.cdb_process_id = cdbecm_briefcase2ec_v.cdb_process_id)) AND status = 10))
	ELSE
		(select * 
		from cdbvp_resp_brows 
		where subject_id in (		
			SELECT subject_id FROM cdbwf_task
			WHERE cdbwf_task.cdb_process_id in (SELECT cdb_process_id
						FROM   cdbwf_process
						WHERE  EXISTS (SELECT cdb_process_id 
										FROM   cdbecm_briefcase2ec_v 
										WHERE  cdbwf_process.cdb_process_id = cdbecm_briefcase2ec_v.cdb_process_id)) AND status = 10))
	END