Is my airbnb income subject to self employment tax?

I have seen several posts regarding but im still unclear. This is my situation:

 

- i have 2 properties

- i clean between guests and provide linens and towels BEFORE the guest arrives. Not during the stay

- i provide wifi. Apts have kitchen, stove, fridge, a/c and tv, sofa, desk and bed. 

- check ins are through lockbox

- i do not provide more than that

- stays are less that 7 days each

- i manage reservations and communication

- im an individual, not a LLC

 

I read in many places that if substantial services are not provided then it is not subject to self employment tax. But i also read in some other places that if stays are less than 7 days it is subject to it.

 

I will appreciate any clarification

 

@taxmodern