Got a 2 way switch that gives 43 volts down one strapper when off, could this be an induced voltage, and if so why isn't it on the other strapper when it is off?
Draw the circuit - think about the permutations. However it is wired, one strapper will always be at line potential. What is on the other(s) depends on which ends the PL & SL are connected.
Scheme 1) PL & SL to L1 & L2, all three terminals of both switches strapped
Light off: Strapper 1 at line volts, strapper 2 at or near neutral via SL & load, common wire could be either.
Light on: Both strappers and common at line voltage.
Scheme 2) PL to one com, SL from the other, L1 & L2 strapped
Light off: One strapper at line volts , other at or near neutral via SL & load
Light on: One strapper at line volts, other floating.
I.e. only in the last situation will one of the strappers be floating and likely to show a ghost voltage, unless the load is O/C in which case one strapper will be floating whenever the switches are in an off state.
A switch that physically sticks after being operated under load, has probably got badly pitted contacts. The tiny weld that forms at each operation, especially if the load has high inrush, can interlock the rough surfaces together. I had this on an MEM grid module, that would jam almost solid after switching about 500W of switch-start fluo, but worked normally off-load.
Rated voltages are nominal based on lifespan and safety and in practice the maximum usable voltage depends on the kind of load. A switch specced for 250V will probably switch 500, but with seriously reduced life and poor safety margin and a tendency to flash over with inductive loads. At very light load it might even handle 750.