Story of my Life! Mothers in the house please I need help, how do I engage my son this summer holidays?

Guys, am still trying to recover from the shock I experienced yesterday with my soon to be 4years old son. I got back home from work only to be greeted with a story of how my son drank a full bottle of Periton medicine. That was all I heard as I ran toward him with a near panick attack, I asked him if he truly drank the whole bottle? He was looking scared and kept mute until I asked him if it was sweet? To which he replied yes. (Couldn't help snapping a smiling) 

While interrogating him, my nanny quickly told me she had already given him some palm oil to drink and that
he vomited the medication afterwards. Then I was a bit relieved but angry and my thought running wild as to what could have happened if no body had noticed he drank the full bottle of the medicine or if it was a more dangerous drug? Oh lord! Thank you Jesus! 

I know a lot of people are going to blame me for keeping medication within the reach of my son, honestly this is the first time and opportunity he as ever had. I kept the medication for my nanny to administered to him after his breakfast, I removed it from the medicine box that morning so my nanny won't mistake another drug for that particular one. Lesson learnt thou, am never keeping any drug within his reach again. Never! 

Now that the holidays are here I don't know how to engage this hyper active young man. Summer schools won't start until after 2weeks of holidays. I have to be at work, he doesn't fear my nanny, he just can't keep calm. He is very inquisitive and want to explore everything, he thinks he is old enough to do everything by him self. Am always screaming and yelling when am at home. When I spank him, his face makes me feel like am the evil step mother... And his baby brother is now crawling with busy hands too. Sigh! 

you see why i  need help and fast... What can I do to keep his busy mind and busy hands busy in a positive way this longggggggggg holiday. any suggestion will be considered. pls share your thoughts.