Q. Hi. can this be used to be a switch for two circuit boards or will need two switches?
A. Hi, thank you for your question. If both boards are wired to the switch then it could be used for both boards at the same time but this is only a SPST switch so only has 2 contacts for ON and OFF operation.
Q. Is this switch suitable to be used in a circuit that has only a voltage of 9v
A. Hi Gerald, thanks for your question. The switch will work ok – although it is much higher rated and intended for AC use primarily and assuming current expected is less than 10A.