Kelkay:
"Black Lights" are UV lights, and are/were routinely used in bug zappers. Replacement tubes used to be readily available at most hardware and feed stores. Th 'bug zapper' tubes fit nicely into Dazor-type fluorescent desk lights. The tubes were not that expensive; but it has been years since I last bought one. Geologists/minerologists use a small hand-held version to confirm rock/mineral identification as many fluoresce under UV light. Have no idea about cost.
Aged sage