The configuration shown was found in an old Poptronics but can be easily assembled using a common calculator photocell. The relay is according to the supply voltage.
Texas Instruments ESD122 Electrostatic Discharge Diodes (ESD) can be ordered from Mouser...
This alternating flashing system uses two-color LEDs. The circuit is from a Radio Electronics...
I found this simple circuit from an English magazine from 1984. The circuit can be easily...