Greetings of the Day from Siddhivinayak Solutionss!!
1) To remove negative energy from your plot, you have to perform Ganhoma in you Premises.
2) Ask your maid or staff to Clean (Mop / Wipe) with a Epsom mixed Salt Water.
2) Tie a Alum in a Black cloth on the main door in a Centre of the Door from Outside.