EmonTx V3.2 upgraded firmware now voltage reads wrong

Yes - but you may well need to follow the very early release notes which describe the ESP8266 conected externally to the emon|Tx. Using the EmonTx v3 with the ESP8266 Huzzah WIFI module.
When you get WiFI working, you will probably want to disable the RFM module. If the software version is recent enough, that can be done via a programmer and the setup menu. If not, then you’ll need to download the sketch, edit it and re-load the emonTx 3.