What if you are paying insurance into the mortgage escrow and you also have a regular home owners insurance and then your house catches on fire?

Generally all your escrow does is to pay the homeowners insurance when the insurance company bills for the renewal. The bank does not select your homeowners insurance for you. You would purchase the insurance of your choice and tell the agent to set it up for mortgagee bill meaning the renewal bills would be sent directly to the escrow provider. Your escrow account also pays your property taxes. Make sure that you do not have two separate policies. The only thing that would happen if you had two policies and had a fire is that they would split payment of the claim as described in the policy under the coordination of benefits. You cannot make a profit by having more than one policy. It is actually illegal to even try such and you would be charged, fined, and imprisoned.