Answer:
Yes.
Step-by-step explanation:
People can sometimes have the same last 4 digits as someone else's social security number. Although it is pretty rare it can happen and different people living at the same time have the same time can have the same last 4 digits. One study does show that "out of 180 people there is an 80% chance that two of them will have the same last 4 digits". While this can happen I wouldn't be worried about anyone having the same full SSN as you.