I have been working on the Modeska (a combination desk, Recordo player
piano and radio) that I bought at the PPCo auction.  It has a small
electric light in the top of the spoolbox.  It uses a pull-chain type
of on/off switch.

What I have never seen before is it also has a pneumatic that has a
bolt and wire on each board that make contact inside of the pneumatic
when vacuum is applied.  It would only allow the light to work when
vacuum is present.  It appears to be original to the instrument.  Has
anyone ever seen this type of setup in an instrument?

Bob Stewart