>>509311383
>>it was from exit signs goy!
Given the quantity and the absence of other radioisotopes, yeah, probably.
Radioisotopes have been used in signage for over a century, for safety purposes:
https://nuclear.duke-energy.com/2016/03/16/lighting-the-dark-with-tritium
and for decorative (usually Radium) purposes:
https://www.epa.gov/radtown/radioactivity-antiques