Visited on May 26 and did a short charge with M-CHARGE RFID. No issue.
The chargers are in the public parking with a sign off the main road "Gemeinde Horw - Gemeindehausplatz". There are parking meter spaces outside but the chargers are inside. There is an M-CHARGE arrow sign just after the gate, but then none at the first turn (you're supposed to go left towards the exit), and one again at the level of the chargers.
I didn't see the parking prices on both of the machines I checked. The only place I was the prices was on the entrance gate. On the payment machine there's only a sign telling you higher denomination bills are only accepted for higher amounts.
I believe there are multiple foot exits, but I only tried the one leading to the police. I didn't see any mechanism to unlock the automatic door with the ticket, but it wasn't necessary as the door was stuck in open position. I hope they are not heating or cooling the staircase because that would be a massive waste of energy if the door never closes.
Bikes not allowed in the parking.