The stock Razor Dune Buggy switch has a 24 Volt bulb in it and it will not last very long when ran on 36 Volts. I also do not suggest running SWT-105 or SWT-106 on 36 Volts because it might get hot and could possibly melt or deform a little.
If the 36 Volt switches sold on eBay are going bad then they are most likely just 24 Volt switches which are being overvolted to 36 Volts which is causing them to burn out.
I do not know of any switches that are the same size and have 36 Volt bulbs in them. What I suggest to do is to use a switch with 24 Volt bulb and use a resistor between the ground wire and the switch to limit the current to the bulb so that it runs on 24 Volts. I do not know how much current the stock Razor switch uses so that would need to be measured to determine what size resistor to use.
A 500 Ohm potentiometer could be temporarily used to dial in the resistance so the right value resistor could be determined. Or an online LED resistance calculator could be used to help determine the resistor value. If using a LED calculator set the Supply Voltage to 36 Volts, the forward Voltage drop to 24 Volts, and the Current to whatever the current that the bulb uses when running on 24 Volts.
Alternatively we could sell you a new SWT-106 along with a resistor that would drop 36 Volts down to 24 Volts so the bulb would not burn out.
Our SWT-106 is almost certainly from a different batch than the original Dune buggy switch is from so it might have a different value bulb or LED in it and I can not use our SWT-106 to determine what value resistor to use with the original Dune Buggy switch, otherwise I could simply recommend the correct value resistor to use.