I once successfully tested 4066 CMOS switch to initiate a keypress on an etched smartphone pad "substrate" with membrane removed. I was interested in having Arduino dial a cell phone interfaced with a 4066 switch matrix. I think the November Nuts-Volts issue highlighting the project which dialed a cell phone was is 2012-13, not sure. I tried the 4066, was planning to build the dialer. Now, I think I will just pay $14.95 monthly for Simpli-____, about $6 more than I would pay for a dedicated prepaid cell phone.

Before fire destroyed nearly everything I owned, I had an AIMS inverter with RF remote. It was nice. I intend to add RF to this less expensive model, but want it as cheaply as possible. ADAFRUIT sells 315 MHz pair, with toggle, momentary, or latch options. I might try a PNP and resistor across the AIMS ON/OFF panel switch. Testing the PNP is easy, pulling the base with a series resistor to GND. The RF pieces total 10$ plus shipping. Nice thing about the 4066 is the low power needed to sustain the ON condition. CMOS requires only the static voltage, great for battery-powered application. It may be reasonable to use a small rechargeable battery with the RF receiver for this use, though it would also be reasonable to derive the needed voltage from one of the solar-charged, 12V 180aH batteries. Other solutions for this may use a latched relay, which requires power, and is expensive, (plus the shipping and handling.)

I will begin by holding a resistor across the open switch, searching for a reasonable value.