The Questions that the Muggle would ask:
1. Why are there flying people on brooms?
2. Who are you?
3. There is nothing wrong with this place, why did you conceal it?
4. What is this?
5. I'm calling the police!
6. I know you! From books! What the...!

Answers:
Tactic- Say it calmly and slowly, without many nervousness. Your nervousness will go to them as well.
1. Hopefully you had been alert enough to let the others know about this problem. If you had not, you will need to erase their memory. This tactic goes for the other questions as well.

2. Say you're from a party. With the wildness, the Muggle would be very much confused and leave.

3. Say that there it's not done. The outside might look nice but the inside or the part where it was not finished, or the finishing touches, the Muggles would say, is not done. In case of problems or accidents, we are being cautious.

4. See 2.

5 and 6: This is the time for necessary measures. If there is nosy and clingy Muggles, these spells will take care care:

1. Obliviate. This is the known spell.
2. Oblivio
3. Oblivion