There are several home automation solutions that would work for this, whether 120V or 12V. An older approach would use X10 based modules with an RF remote control. Now, you can find better alternatives including Z-Wave and Insteon. I use the latter along with an ISY-99i to control a large number of Insteon devices in the home (including some low voltage lighting around the property). Insteon is based on a dual mesh powerline/RF communications protocol. Several vendors sell Z-Wave modules that would also work. I believe Z-Wave is entirely based on RF alone. The overall pricing is roughly similar. For both Z-Wave and Insteon, you would need to purchase at least one module to switch the load, and you would need an RF remote. For Insteon, you would also need some way for the remote to communicate with the module. They now sell dual band modules for this purpose. For both Z-Wave and Insteon, you can also purchase servers that allow you to schedule the modules to turn on and off at specified times, respond to macros (i.e. if I hit this one button, all of my lights in the backyard will come on at pre-programmed levels, and will turn off after 1:00 AM automatically, etc). These servers also allow remote access, and allow you to use a smart phone or remote computer to control the modules, which can be handy.
To make a long story short, what you want to do is quite easily done. There are several routes, it just depends on how reliable you want this, and how much control you want.