2.5v red tipped flasher mini Christmas light replacement bulb

This was found also in my stash of Christmas light bulb drawer. This has a bimaltalic thermal switch, when power is applied, the filament turns on, and then heats up the bimaltalic switch. After that, it disconnects from the other lead, then contracts. It'll repeat that cycle till you turn it off.

This will make the incandescent light set flash. If its a parallel set, than you might need more of these bulbs to make the whole light set flash. Of course it won't be in sync.

See it in action: (copy link, and paste it in a new tab.) https://www.lighting-gallery.net/gallery/displayimage.php?pos=-143265