Update:
I have received my copy of Joseph Hughes' death certificate. I wanted to post the information here in hopes that I might get some help in finding out any more information, particularly where exactly he worked and his family members. Would love to know how and if the Samuel Hughes and John Hughes listed on the certificate are related to Joseph as well. Thank you so much, I really appreciate any help!

Here is the information on the certificate:
-Registration District: Wrexham
-Death in the Sub-District of: Wrexham
-In the Counties of: Denbigh & Flint
-When and Where Died: July 10th, 1867, Holt Street, Wrexham
-Name and Surname: Joseph Hughes
-Sex: Male
-Age: 45
-Occupation: Silver Refiner
-Cause of Death: Pneumonia (Certified)
-Signature, Description and Residence of Informant: X The mark of Samuel Hughes, Present at the death, Brymbo
When Registered: July 11th, 1867
Signature of Registrar: John Hughes