Craig, thanks for the response. Anyway you could provide some pictures and perhaps more detail?
I don't have any photos of my relays, yet, and we're currently packing to head west for several weeks.
Basically, you would need to buy a SPST or DPST type relay with coil rated at 12vdc, and contacts rated at 120vac, for whatever amperage you need to control
(30 amps is not uncommon, and I'd recommend going with that rating). The coil would be connected to your low voltage controller output or to a common
switch (rocker, toggle, etc), and the load hot wire would be connected across the contacts of the relay. When you flip your switch, it energizes the relay
and closes the contacts, completing the 120vac circuit and turning on whatever load you have connected to it.
Check DigiKey for relays. They're not very expensive.
A note of safety: because the relays are being used to control 120v loads, and have exposed terminals for the 120v connections, you need to enclose the relays
in a covered electrical box of some sort.
I can discuss this further with you, if this description is not clear. Send me an email if you need more.
I might be able to get some photos next week when we're in Colorado.