hi need some help. i'm looking at changing my existing light and fan switches to smart switches.
1. can i just buy any smart switch like this and swap them out for the old existing one?
2. do i need a hub of some kind or can they just work via wifi once setup? i have smart timer plugs like this and they dont require any hub.
3. do they need a capacitor installed too? or is there any smart switch that doesnt require capacitor, or hub?
i'm looking for the simplest solution

1. normal conventional switch usually have live and grounding wire, no neutral.. these switches usually with LED indicators will require a neutral wire, which means you need todo rewiring all over again or tapping from another neutral source.. alternatively, you can look for switches that only requires live and grounding wire such as Xiaomi smart switch..
2. you dont need a hub coz usually these will work thru wifi then apps on your phone.. but of course if you want to make it more smarter like voice command at home, you'll need a hub like google dot etc.
3. i think back to answer no.1

1. You need to differentiate the smart switch require Neutral wire or not. In Malaysia most of the default light/fan switch provided by developer do not have Neutral wire. So you will need to find out your existing switch come with Neutral wire or not.
2. The smart switch link that you provided DO NOT require hub. Just WIFI will do. You will need to install the Tuya/Smartlife app and setup.
3. Depends on the answer in question 1. If the switch does not need Neutral wire, then it will require capacitor. If the switch needs Neutral wire, then NO capacitor required.

Smart switch required power to stay operated (via Neutral wire). Without Neutral wire, no power provided to the switch. Hence there is a type of smart switch do not require Neutral wire, but then it will need the capacitor connected at certain sequence light in order to supply the minimal power to the switch to keep it operating.

mine is single phase no neutral wiring. thanks for the info

thanks for the info re capacitors. now it makes more sense to me