Using two small appliances, such as a microwave and a refrigerator, on one circuit can be risky and may lead to electrical overloading. It is generally not recommended to plug multiple high-power appliances into the same circuit simultaneously, especially if they have a high wattage.
The reason behind this is that both the microwave and the refrigerator are high-power appliances that draw a significant amount of electricity when running. When they are both operating on the same circuit, it can exceed the circuit's capacity and cause the circuit breaker to trip or the wires to overheat, potentially leading to a fire hazard.
To ensure electrical safety and prevent overloading, it is advisable to plug each high-power appliance into a separate circuit. Most refrigerators have dedicated circuits in modern homes, but microwaves might share a circuit with other smaller appliances in the kitchen.
If you are uncertain about the electrical setup in your home, it's best to consult with a licensed electrician to assess your circuits' capacity and ensure they are correctly wired to handle the load of your appliances. They may recommend installing additional circuits or redistributing the loads to prevent any potential hazards.