In Google I found a wireless intercom schematic. It is very complicated. It uses 30MHz FM for its audio but it uses old fashioned "voice switching".
Voice switching is when I talk then you hear me only if you are completely quiet with no background sounds. I hear you talk only if I am completely quiet with no background sounds. There is only one radio audio path at a time.
We keep cutting off each other and background sounds also cut us off. Most wired intercoms also have this problem. Most handsfree speakerphones also have this problem.
Maybe there is a complicated wireless intercom for a glass window that uses two modulated infrared paths for the audio? But since it needs a wired power supply then why doesn't it use simple wires for the audio paths?
Maybe it can be done with bluetooth transmissions? Nice and complicated.
When using two audio paths, how would you prevent acoustical feedback howling where a sound goes in my mic, out your speaker then into your mic and out my speaker then in my mic again ..... and the sound goes around and around.
Maybe the acoustical feedback can be prevented with a nice complicated digital echo canceller circuit?
Polycom speakerphones use a digital echo canceller circuit so the voice path does not switch and you do not get cutoff. Check their very high prices.
I think the student is learning how to solder, not to design a circuit nor understand how it works. He/she should select a simple circuit.