It's not uncommon for people to hallucinate while grieving the death of a loved one.
If you are still hearing things that are not there, or seeing things that are not there, you clearly need some form of psychatric help, as those are hallmark symptoms of a psychotic disorder, eg schizophrenia.
If anyone wants immediate advice don\'t hestitate to contact to me on AIM (AOL instant messenger) - aim: vodkasmodka
Eccentric! Not egocentric!