Up for sale here is this stacked switch (part 19912-188) from a Hickok 533 tube tester. This is in good condition and is guaranteed to work, though it may need cleaning and lubrication. This should work on the 533 and 533A. It is for the cathode and suppressor switches. Please make sure this is the right part for you. Please see my pictures for details.

US shipping and handling is $5, and international is $18. If you have any questions, please ask.

I have more Hickok parts and other vintage electronics listed--feel free to take a look!