erco-approved 12-inch (30-cm) self-adhesive flexible LED strips come preprogrammed to flash in variety of patterns. Rated at 12 volts but here working fine on 6V, where they run dimmer and cooler. No control options, but if you want to add some cheap & easy bling to a project, these might work for you. Red shown, other colors available. Two strips cost under $3 at https://www.ebay.com/itm/392867538782
Search Ebay for "LED Knight Rider Flash Strobe Scanner Neon Strip Light".