Yes, it is safe to leave a plug in the outlet, even if the device is not in use. Modern outlets are designed to provide continuous power without causing overheating or other problems.

Leaving a plug in the outlet can even be convenient, as you can easily connect the device when you want to use it. However, it is important to take some precautions:

1. Make sure the plug is firmly in the outlet and that there are no loose connections. A loose plug can cause overheating and pose a fire hazard.

2. Regularly check the condition of the plug and cord. If you notice signs of damage, such as worn insulation or exposed wires, remove the plug from the outlet and replace it if necessary.

3. If you are not using a device for a long period, such as during vacations, you may choose to unplug it to save energy and reduce the risk of any electrical issues.

It is important to be aware of safety and regularly check the condition of plugs and outlets to avoid potential risks.