How can I find out the cause of death of a Mr. Fulginiti in Washington
State in about 1992

Do you know where he lived? Where he died (what city or county)? What
his first name was? What date he died on?

His first name may have been Joseph ~ Not sure.  His family resided in
LaConner, WA 98257  ~ That's Skagit County.  He was a fisherman so may
have possibly been at sea at the time of death.  He may have been in
his 30's.

In order to obtain the death certificate, you will need more
information.  Specifically, you will need to know the person's name,
the county of death, and the approximate date.

Full information on how to obtain death certificates can be found on
this page:

Death Certificate Ordering Information
http://www.doh.wa.gov/ehsphl/chs/death.htm

Best wishes in your search for information.  I am not providing this
as an official answer because I can't be certain that the death
certificate will indicate the cause of death in the detail you need
it.