This definition from Webster's shows what Catholics mean when they "pray to" someone for something, we're doing exactly what you say, we are "praying" or "asking something for somebody":
(1)PRAY : to ask (someone) to do something usually humbly or as an inferior to a superior : CRAVE (prayed the king to give them land) — often used as a function word in introducing a question, request, or plea (pray tell me the time) (pray let us hurry) — compare PLEASE (2) : to ask earnestly for (something) : supplicate for : BEG (I know not how to pray your patience— Shakespeare) c : to ask (someone) for or on behalf of another (we pray you ... be ye reconciled to God— 2 Cor 5:20 (Authorized Version)...
Webster's Third New International Unabridged Dictionary
“Praying FOR someone is not the same as praying TO someone.”
Mea culpa! Perhaps I could’ve been clearer by saying,
Praying FOR someone is not the same as praying TO that same person”
Where in the Scriptures does anyone pray to the saints in heaven? For any reaason?