Yes, it is generally safe to use a WiFi extender as long as it is set up and used correctly. However, it is important to note that using a WiFi extender can potentially create security vulnerabilities in your network, especially if the extender is not configured properly or if it is placed in a location that is easily accessible to unauthorized users.

To ensure the safety of your network, it is recommended that you use a reputable brand of WiFi extender, keep your firmware up to date, and use strong passwords and encryption. You should also take care to position the extender in a secure location and limit access to your WiFi network by using a strong password and disabling guest access.