My husband is retiring at 65 this year. I am going to continue to work. My question is when I retire at 64 (another year away) can I start with RR spouse and then switch to Social Security at 66 for the higher benefit?
You wouldn't exactly 'switch', but assuming that you meet all of the requirements for both benefits you could potentially file just for Railroad spousal benefits initially and then later file for your Social Security benefits. I can't say whether or not that would be your best strategy, though. That would depend on your potential benefit rates from each program.
If you follow your plan, what you will receive is the higher of your a) Social Security benefit rate or b) your Tier 1 Railroad rate, plus any Tier 2 Railroad benefits for which you qualify. Thus, you would likely only benefit from filing for Social Security if your benefit rate is higher than your Tier 1 Railroad rate, and if it is then you may be better off waiting until age 70 to file for your Social Security benefits.