This is a cheap audio switch. It switch not just the sound but the headset microphone to the desktop mic.
Step 1: Requirements
3 mono slot, for microphones
1 two way switch
some two component glue putty
1 old mouse
It's just 510 HUF cca. $2.
Step 2: Assembly
Step 3: Wiring
Step 4: Installing and conclusion
I make a sign the mic input, its easier plug.
My wife is full of smiles, at least :)