I have in my home a National Wheel-O-Vator, Model DH4C_R0 elevator, installed in 2000.
The 3rd-floor landing door interlock circuit is broken because the internal microswitch capsule has failed, cutting the 24VAC safety loop. The ALR light is off.
I have on hand the proper replacement interlock switch (Door Shut/Lock), shown above and at access2parts.com/nwov-dmi-switch/.
I need a skilled technician to unbolt the failed microswitch capsule from the landing frame assembly, swap the wire leads onto the new switch terminals, and mount it back into place.