Just for good measure, a breakout board for twin Songle SRD series relays to fit the Dangerous Prototypes standard PCB size DP5050.
Released under Creative Commons Attribution Share-Alike 3.0 License, the schematic and parts of the layout derive from Sparkfun Electronics COM-11041 designed by N. Seidle and Joel Bartlett. Thanks Sleepwalker3 and an anonymous commenter for helpful design suggestions. The latest version of the board (RD02) has the relays in a different orientation to maximize the clearance and creepage between the high voltage traces:
The component values are designed for VCC = 5 VDC. For VCC = 12 VDC, use R4/R5 = 3.3 KΩ.
See the previous post for a single relay on a DP5031 PCB.
Mains electricity can kill. If switching high voltages, make sure to mount this PCB in a well-insulated or grounded enclosure. Apply conformal coating to the finished board for electrical insulation and environmental protection. Make sure your loads are properly protected by fuses.