I've got an older house, mid 60s or so, with mostly original wiring. I'd like to install the KS240 in a bedroom; switch box has live and neutral wires, but no ground wire though. Current basic switch is in a metal box, confirmed there is no ground connected to back of box. Is a ground connection absolutely required for proper function of the KS240 switch?  Breaker panel is on complete opposite side of house, would like to avoid having to run new wire through wall and attic just to get this switch to work properly, probably cost prohibitive just for this one switch.