It is the responsibility of the Postal Service to change burned- out light bulbs in leased facilities. The T-12 florescent light bulbs are no longer available in the catalog; however, they are available elsewhere.
The Postal Service has advised its personnel not to substitute T-12 bulbs with T-8 bulbs as they do not work even though they will fit in the fixture. The ballast will burn out immediately since they are made exclusively for the T-12 bulbs.
If USPS causes the ballast to blow, it will be responsible for replacing the ballast and likely the entire light fixture.