Lamproom Sealing Wax.
Made from wax. Size 4″ x 1/2″ x 1/2″ inches.
This sealing wax with a wick was used to seal the release pins in place in the cap-lamp bezel so that no-one could access the air tight lens and bulb to expose the electrical parts. The wick would be set alight to melt the wax enabling it to drip into the recess that housed the release pin.
If or when the bulb had to be replaced the wax would be scraped out by the lamproom staff, a new bulb would be installed and the wax replaced, covering the release pin.