The ADG1219 is a monolithic iCMOS® device containing an
SPDT switch. An EN input is used to enable or disable the
device. When disabled, all channels are...
ADG1219 on Analog.com
the on-resistance chart has curves with a supply votlage of +/- 4.5 V .
what would the worst case on-resistance be when the device is powered at +/- 3.3V ?
The ADG1219 is not recommended for +/-3.3V supply.
You could have a look at the ADG619 or ADG1636.