Unplug microwave. Open door of Microwave. Insert phone. Your cell signal will probably be lost. If not, (due to the missing sixth wall), build a curtain of aluminum foil to close-off the sixth wall. Poke a small hole for looking-through. Use USB-OTG keyboard/mouse.
Microwaves. You can also buy Faraday bags, but (almost) everyone has a microwave.
But you can’t close yourself in your microwave.
Unplug microwave. Open door of Microwave. Insert phone. Your cell signal will probably be lost. If not, (due to the missing sixth wall), build a curtain of aluminum foil to close-off the sixth wall. Poke a small hole for looking-through. Use USB-OTG keyboard/mouse.