Will,
Tritium is a radioactive substance. Only and just slightly. but it is radioactive. The amount in these glass vials is nominal and you are in no danger, except please make sure they are disposed of correctly in the 'Decades' to come. The contained liquid can have localised effects if ingested or got onto your skin.
Having said that, I also use them (or used to) for night lights on my fishing floats.
It's always good to see someone looking to do something different with unusual items, great effort.