k-man

It doesn't really matter if you switch or not.

Let's consider 2 players - Alex and Bob. Alex always switches after picking the first envelope and Bob always keeps the envelope he picked originally. The amounts in the envelopes are always the same  and they play this game many times in succession. If switching strategy was beneficial then Alex should end up with more money than Bob, but in reality they will have the same amount of money. Since both pick randomly, both strategies have 50% chance of picking the envelope with the larger amount, so both players will get the large amount 50% of the time and small amount 50% of the time.

Whatever the amount of money you found in the envelope you pulled let's call it X. Unless X is 1 penny, it's a 50% chance that the other envelope has higher or lower amount. The potential gain by switching is X. The potential loss is X/2. So, by switching you gain X * 1/2 - X/2 * 1/2 = X/4 on average.

Abbreviations: Truth Teller=T, Liar=L, Random=R

First press LT button.

If you get shocked then it means that either 1) you=T OR  2) you=L, left=T, right=R, so press the LR button next. If jolted again, then you=T, left=L right=R. Done (2 presses, 2 jolts).

If the second press was safe then press RT. If jolted, then you=T, left=R, right=L. If not, then you=L, left=T, right=R. Done (3 presses, 1 or 2 jolts)

If the first press was safe that means either 1) you=R OR 2) you=L, left=R, right=T, so press the CT button next. If jolted, then you=R, left=L, right=T. Done (2 presses, 1 jolt)

If the second press was safe too, then press LF or RR button. If shocked then you=R, left=T, right=L, otherwise you=L, left=R, right=T. Done (3 presses, 0 or 1 jolts)