This is probably the simplest idea to generate flashing light from an LED using AC. The circuit is relatively the simple way of flashing one or more LEDs from a high voltage DC obtained from Mains.

LED flasher circuit With cycling safety in mind, I bought a pair of low power red LED things that replace the bungs in the end of drop handlebars. They are a neat way to get a bit of extra visibility ...

A pair of alternating flashing LEDs makes an excellent visual alarm. One of the LEDs remains illuminated, so there's little chance the alarm will go undetected, even by a casual glance. Several ...