thedvshow

VHF is the way to go in your situation. Interference from other devices
would happen if you go UHF (obviously)

A variant on wireless intercoms (apart from VHF and UHF entirely) is
the IFB, or cue system. This type of system is used for listen-only
applications such as monitoring an ongoing program, cueing talent, and
where the return path for the person's voice is a microphone (e.g., an
on-camera television announcer receiving cues from a director).

The audio from an intercom line, a program source or both is input into
a transmitter, typically housed in a 1RU or half-rack enclosure. One or
more beltpack receivers with headphones or ear buds are tuned to
receive the signal from the transmitter. Some of these beltpacks have
two receivers on different frequencies, so that the user can switch
between two different audio sources.

Wired IFB systems are also commonly used as additions to wired intercom
systems. These units can have an additional feature that allows the
incoming program material to be interrupted or ducked when a voice cue
is introduced.