It is possible to hardwire with UL rated
devices. I have a bunch of 24VDC relays
controlled by a computer in my home (both
120V & 240V loads). Getting UL rated relays
should be relative easy. The NEC (National
Electrical Code) indicates that the
insulation must be compatible with the
highest voltage in the junction box. I got
this information from our local city
electrical inspector.