Reading these responses I think we all agree
Read the lease and see if the issue was addressed. You also need to see if the lease states how the house is going to be shown and what you are obligated to do to allow people in to see the house.
If the lease is not clear than you should consult an attorney.
This really should have been explained when you signed the lease too.
Check your lease, because it probably has a clause about resonable access, not only for the landlord to inspect the property, but for people wanting to look at the house as potential buyers.
Of course if you have a good relationship with the landlord, you can ask for reasonable times that don't affect your "quiet enjoyment" (ie: like if you work nights and sleep days, no showings before a certain time) , but again the key word is reasonable for all parties involved.
Read your lease. It should have a provision that allows the owner to sell the home. Sometimes even if the home is sold you may have some rights based on your lease. If you don't see anything or need further help contact a local Real Estate Attorney and ask for assistance. We are not attorneys and can't give legal advice.
As for your right to quiet enjoyment, most leases have a clause that states that the owner can show the apartment to prospective buyers or tenants. They do have to provide you with 24 hour notice though and you can ask that the rental only be shown within specific hours, if you have children or other needs that would limit the hours for showings.
If you would like a copy of the NJ Landlord/Tenant handbook, just reach out to me via Trulia or my website below and request a copy. I can email it to you.