Thanks for the help. I am trying to work on a project that will use relays to switch between different circuits that connect different parts of my widget to test for insulation resistance. The insulation resistance is at a 1000V not sure at the moment the exact current but it is low. I would like to know if i could use a relay like the ones here:
They use about a volt for control voltage, is there anything I am missing?
Link to insulation tester i will be using:
Yes. Of course, check the datasheet, but these ~1V SSRs have an LED with no resistor (or other current limiting). So, it's like any "regular little" LED or opto-isolator... You can use it with almost any control voltage, you just have to calculate the proper resistance for the necessary current.
It's up to you to make sure the overall design is "safe". 
Note that solid state relays are usually for switching AC or DC and they are not interchangeable. Most AC solid state relays are built with TRIACs and a TRIAC latches-on until current drops to zero (the next AC zero-crossing), so with DC they latch-on and won't shut of 'till power is removed.