Are there risks in using a switch rated for a lesser voltage than what my application is using?
For instance, I am using a switch rated for 2A @ 30V DC on an application that is using 1A @ 36V DC.
Since my current is lower, can my voltage be higher?

Here is the switch I am using:
https://www.digikey.com/en/products/detail/nkk-switches/sb4011ncm-2a/1049884
Here is a link to the datasheet: HERE

 

The difference of 6v is probably not going to make a difference, also being under 60v it is not considered a safety hazard.
Particularly that the circuit current is lower.

 

Contact ratings for voltage and current usually relate to the claimed switch life number of on/off operations. The voltage rating is related to contact arcing while the switch is opening and when it is in the open position. The current rating is about the contact heating as current is flowing through the switch.
Considering the normal safety margin switch makers apply, it is not likely that there will be any problems using that switch.

 

Does the load have any inductance?