On the main page of this module there is this statement: “This module includes one relay capable of controlling up to 10A-250VAC”.
If you take a look at the back of this module, you will see that there is a GND polygon pour. NC trace that comes from relay has a clearance of 10-20 mils or alike. The same situation is with other traces that come from relay to terminal block, but they are a bit harder to see.
Either I am missing something here or this module on no circumstances should be used to switch high voltages.