Regular single pole switches used for lights. Are dry contact switches.
The spring wind timer switches at HD, are also dry contact.
Now the question remains if the switching contact/s on the control board are dry contacts (a/o powered switching), too. But even if the control board switching terminals are not dry contact type, it'll still work. Only the voltage and amp. rating (of the switches) must be compatible.!
The terminals that you connect a switch to. Can't be dry contacts.
if they were. then nothing would work. Since there would be no power/electric for the switch to control.
I withdraw that statement on a/c control. But in intercom systems manufactured by Aiphone (this is not meant as an endorsement. Just for useful information purposes. M.K.) where you can control an independently powered entry door buzzer system from the IC unit. those terminals are Dry Contact. Yes. I see the distinction. Thank You.!