Court of the Bishop of Exeter
A general explanation of probate records in England, is given in the article England Probate Records.
Printed and Published Indexes
Virtually all records for this court were destroyed in 1942, but don't give up until you have searched the manuscript collections and the all other possible courts. These include:
Copies of some post-1796 probates may have been deposited in the Estate Duty Registers.
Family History Library Records