Q about letter from employer!!

Does the letter from a spouses work place get checked? like do they phone his work place to verify the info? or they just wanna make sure he/she works?

They might but probably not unless they have reason to suspect something is up.

The letter would have to be on letterhead, which would have the employer's address and phone number, so they could contact them if they wanted to.  Although as Britwife said, they probably wouldn't do it unless something aroused their suspicion.