Hey there! I recently tried my hand in Wild, and one of the first decks I built was this Aggro Secret Paladin. I've only played it in the lower ranks so the win rate is absurdly high, but if you're new to Wild, give this a try. I went on a 15-game winning streak with this all the way rank 15. I'm still trying to figure out the optimal combination of secrets (I just included the strongest ones) so this deck is a work in progress, but it's been fun to play so far. I'll update this the more I rank up.

Strategy

Early Game:

The goal is to swarm your opponent with a wide board, which are ideally protected by your secrets. You're always the aggressor, so your focus on the early game must be to build a threatening board with your Secretkeeper, Sunreaver Spy, Bellringer Sentry, or Corpsetaker. Ideally, you've brought your opponent down to 20 health or less by turn 5.  

Mid-Game:

If your opponent somehow manages to clear your board, Call to Arms is a great reload. I recommend that you don't overextend your board if you don't have Call to Arms at the ready, as it's such a good card that allows you to keep the pressure up. Following it up with a Sunkeeper Tarim or Mysterious Challenger on turn 6 or 7 is usually a game-winner, since you opponent will either have to deal with an army of 3/3s or try to get through 5 different secrets protecting your board. 

Late Game:

You always want to push damage on every turn, so failing to build momentum in the early game can really hurt. Still, the deck is equipped to swing momentum in your favor fast with cards like Call to Arms, Mysterious Challenger, and Bellringer Sentry with the way they instantly affect the board. 

Card Priorities

Secretkeeper

Bellringer Sentry

Corpsetaker

Call to Arms

Secrets (mostly as activators for Secretkeeper, the spies and Mysterious Blade, but Noble Sacrifice, Redemption, and Autodefense Matrix are ideal)

Key Cards

Never Surrender! - I initially included just one copy of this card, but it works wonders for this deck so I cut one Autodefense Matrix and added another copy of this. Since you're almost always going to have minions on the board, triggering this will result in some fat minions to negate quite a number of board clears. 

Wickerflame Burnbristle - Strong turn 3 play to protect minions you've played in turns 1 and 2, and an additional activator for Corpsetaker. Can be replaced with Commander Rhyssa, a card that I don't have yet. 

Corpsetaker - A fantastic card that you can play if your opponent managed to remove your wide board, since its divine shield really makes it sticky. I didn't include any windfury minions in this deck as I don't think it's needed, and it takes up space. 

Call to Arms - The most important card in the deck. It doesn't matter what it pulls (even a Sunreaver Spy without buffs is a solid 2/3 body); it will cause problems for your opponent, as they either can't deal with your board or be baited into using removal. 

Sunkeeper Tarim - Useful card no matter the situation. You can play it on a wide board then hit your opponent in the face, or bring some big enemy minions down to a manageable 3/3. 

Mysterious Challenger - Very strong card in the deck. Even if you only have a few secrets left in the deck, it'll still leave behind a 6/6 body in play that's difficult to remove. Playing this on curve can be a big swing, or give you momentum to get back if you're behind. 

Replacements

Irreplaceable cards: Call to Arms, Bellringer Sentry, Mysterious Challenger

Wickerflame Burnbristle - This is the best replacement candidate in the deck. Commander Rhyssa is the obvious replacement, but if you don't have her, Muster for Battle will do quite nicely. SN1P-SN4P could work too. 

Corpsetaker - Solid turn 4 play, but can be replaced with Truesilver Champion.

Mysterious Blade & Sunreaver Spy - They're key cards in the deck because of their synergy with secrets, but can be replaced with Amani Berserkers and/or Loot Hoarders, since this deck could use some card draw. 

Getaway Kodo - Just add another Autodefense Matrix, though that'll lessen your secret variety for Mysterious Challenger. 

Subject 9 - Pretty important for hand reload, but if you don't have it, adding two copies of Hidden Wisdom will do. 

Replays

vs. Warrior: https://hsreplay.net/replay/yXgHvhcRKtsd9rXpRZnvuH

vs. Mage: https://hsreplay.net/replay/pAaT4DY8yP5BB7FSdRC6WR

vs. Hunter: https://hsreplay.net/replay/9frcnYLwnSTPBaTWeSFwxZ

vs. Druid: https://hsreplay.net/replay/QmVD4LHrB8d2CpLx2j4SmU