To ensure that your Selenium WebDriver script waits for an alert to appear and then accepts it, you can utilize the `Wait` functionality.

In C# -

public static void HandleAlert(IWebDriver driver, WebDriverWait wait)
{
    if (wait == null)
    {
        wait = new WebDriverWait(driver, TimeSpan.FromSeconds(5));
    }

    try
    {
        IAlert alert = wait.Until(drv => {
            try
            {
                return drv.SwitchTo().Alert();
            }
            catch (NoAlertPresentException)
            {
                return null;
            }
        });
        alert.Accept();
    }
    catch (WebDriverTimeoutException) { /* Ignore */ }
}

The equivalent method in Java is as follows -

public static void HandleAlert(WebDriver driver, WebDriverWait wait) {
    if (wait == null) {
        wait = new WebDriverWait(driver, 5);
    }

    try {
        Alert alert = wait.Until(new ExpectedCondition<Alert>{
            return new ExpectedCondition<Alert>() {
              @Override
              public Alert apply(WebDriver driver) {
                try {
                  return driver.switchTo().alert();
                } catch (NoAlertPresentException e) {
                  return null;
                }
              }
            }
        });
        alert.accept();
    } catch (WebDriverTimeoutException) { /* Ignore */ }
}

This code will wait for 5 seconds until an alert appears. If the expected alert does not show up, you can handle the exception accordingly.

Have you surrounded your switch statement with a try/catch block? You might also consider incorporating a wait timeout to check if the alert appears after a designated delay

try {
    // Implement a wait timeout prior to this command to ensure 
    // that you are not attempting to access the alert too quickly.
    Alert alt = driver.switchTo().alert();
    alt.accept();
} catch(NoAlertPresentException noe) {
    // No alert detected on the page, continue with the test.
}

AlertHandlingException 

occurs when an unhandled alert box unexpectedly pops up during execution. To remedy this, it is important to configure the code to respond appropriately when an alert box is encountered. By implementing this solution, you can effectively resolve the issue at hand.

       try {
            System.out.println("Opening page: {}");
            driver.get({Add URL});
            System.out.println("Wait a bit for the page to render");
            TimeUnit.SECONDS.sleep(5);
            System.out.println("Taking Screenshot");
            File outputFile = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
            String imageDetails = "C:\\images";
            File screenShot = new File(imageDetails).getAbsoluteFile();
            FileUtils.copyFile(outputFile, screenShot);
            System.out.println("Screenshot saved: {}" + imageDetails);
        } catch (AlertHandlingException ex) {
            try {
                Alert alert = driver.switchTo().alert();
                String alertText = alert.getText();
                System.out.println("ERROR: (ALERT BOX DETECTED) - ALERT MSG : " + alertText);
                alert.accept();
                File outputFile = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
                String imageDetails = "C:\\Users";
                File screenShot = new File(imageDetails).getAbsoluteFile();
                FileUtils.copyFile(outputFile, screenShot);
                System.out.println("Screenshot saved: {}" + imageDetails);
                driver.close();
            } catch (NoAlertPresentException e) {
                e.printStackTrace();
            }
        } 

Once the click event has been triggered, include the following code snippet to manage it:

    try{
         driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
       }
 catch (org.openqa.selenium.UnhandledAlertException e) {                
         Alert alert = driver.switchTo().alert(); 
         String alertText = alert.getText().trim();
         System.out.println("Alert data: "+ alertText);
         alert.dismiss();}

Now you can proceed with other actions before closing the driver.

DesiredCapabilities firefox = DesiredCapabilities.firefox();
firefox.setCapability(CapabilityType.UNEXPECTED_ALERT_BEHAVIOUR, UnexpectedAlertBehaviour.IGNORE);

To handle unexpected alerts in Firefox, you can also use UnexpectedAlertBehaviour.ACCEPT or UnexpectedAlertBehaviour.DISMISS

Dealing with a similar issue, I implemented the following changes:

try {
    click(myButton);
} catch (UnhandledAlertException f) {
    try {
        Alert alert = driver.switchTo().alert();
        String alertText = alert.getText();
        System.out.println("Alert information: " + alertText);
        alert.accept();
    } catch (NoAlertPresentException e) {
        e.printStackTrace();
    }
}

And to my surprise, it resolved the issue flawlessly.

I decided to give this code a shot and surprisingly, it worked flawlessly on my Chrome browser.

try{
    System.out.println("Waiting for Alert");
    WebDriverWait wait = new WebDriverWait(driver,10);
    wait.until(ExpectedConditions.alertIsPresent()).dismiss();
    System.out.println("Alert Displayed");
}
catch (Exception e){
    System.out.println("Alert not Displayed");
}