Listview update content each timer tick

Hello

I'm making simple application which retrives list of Wi-Fi and print necessary info in the ListView.

public void GetWiFiInfo()
        {
            foreach (WlanClient.WlanInterface WiFiInterface in client.Interfaces)
            {           
                Wlan.WlanAvailableNetwork[] networks = WiFiInterface.GetAvailableNetworkList(Wlan.WlanGetAvailableNetworkFlags.IncludeAllAdhocProfiles);
                foreach (Wlan.WlanAvailableNetwork network in networks)
                {
                    Wlan.WlanBssEntry[] list = WiFiInterface.GetNetworkBssList(network.dot11Ssid, network.dot11BssType, network.securityEnabled);

                    foreach (Wlan.WlanBssEntry entry in list)
                    {
                        string BSSID = BitConverter.ToString(entry.dot11Bssid);
                        ListViewItem item = new ListViewItem(GetStringForSSID(entry.dot11Ssid));                     
                        item.SubItems.Add(BSSID);
                        item.SubItems.Add(entry.rssi.ToString());
                        item.SubItems.Add(network.dot11DefaultAuthAlgorithm.ToString());  
                        wifiListView.Items.AddRange(new ListViewItem[] { item });
                        
                    }
                }
                
            }
            
        }

So, this is the function which populates ListView.

I've also added timer, which I want to use to update ListView every second (calling this function in timerTick event causes adding items to the listview one after another, e.g. we have 1 network - after 10 secs we have 10 same networks on the list)

The problem is, I have no idea how to do that. List of networks isn't constant (else I could use Items[number].SubItems[number].Text property), becayse if we move, new networks may be in the range, so we need to add another row. Anyone has idea how to update whole list?

I was thinking that maybe there is a way to remove current item and add new one?