I got this new switch and it was connected to ESP home + Home Assistant.
When updating the firmware, something went wrong and now the switch doesn’t show Wi-Fi light or indicator light. It disconnected from Wi-Fi
Is it possible to factory reset and get back to the working condition?.. 
Sadly there’s no such thing as “factory default” in esphome. You’ll have to open it, connect usb-uart device to appropriate esp pins (rx, tx, gnd), boot it into bootloader and flash it via serial.
Do you have AP/captive portal configured?