I have purchased this Relay Board http://www.sainsmart.com/sainsmart-8-ch-ssr-5a-dc-dc-5v-220v-solid-state-relay.html
This board uses a mager GJ-5FA-L relay with input ranging from 3-32VDC and a coil switching range of 5-220VDC at 5A.
I have done some research and have found relay power ratings - AC vs DC stating:
...relays are allowed to switch only a fraction of the AC power if DC. It's not uncommon to see 250V AC relays only rated for 30V DC....
This would seem to reason that since this relay can handle a maximum load of 220VDC that it would easily handle 120VAC. But what concerns me is a comment on the product page on amazon https://www.amazon.com/SainSmart-DC-DC-5V-220V-Solid-State/dp/B00TEUEW0G stating:
Note that the load is only switched in one direction. If you reverse the + and - on the load connection, current will flow even with no voltage applied to the input circuit.
I know that AC is alternating current and flows in both directions, does this mean that if this relay is applied a 120VAC current that it will fail?
My application is using raspberryPi GPIO pins to switch on and off Christmas Lights that are string 120VAC.