The burial of John Campbell Esqr (aged 79) of Mount Pleasant is registered in St. Werburgh's 1st July 1820. https://churchrecords.irishgenealogy.ie/churchrecords/display-pdf.jsp?pd...
Some biographical detail can be found here https://carrigoran.blogspot.com/2014/03/john-campbell-1740-1820.html.
There is a burial register for a Susanna Campbel aged 52 whose cause of death is 'killed' although it appears to be St Catherine's burial register.