It's simpler to buy than to build unless the "building" exercise is part
of the goal (hobbyist) or the "buying" is just 'way too expensive.
Regarding home automation products, the commercial baseline is the X10
product line. See what's available from them and, once you've assessed
the capabilities and limitations against your own requirements, it may
be possible to provide more focused assistance.
It is most likely someone that english is a second (or third, or fourth)
language and that is the best they could do AND you should have the
common courtesy to respect and understand that.