I thought she was just hiding in one of Eileen's many rooms

She is hiding in one of Phelans apartments. She knows nobody goes to look at them. Probably the one that Eileen furnished when she was made director of interior and tile design.

So many plot holes. You can't just send off for a credit card online then it arrives. You have to sign the paperwork and send it back for one thing. And once the pin comes you have to activate it too.
Caz has somehow got a flat and can install and fit cctv, which is so discreet (how is it powered?!) that she has no qualms sending the police around to do a search (which you can't do without a warrant and other than a mentalist leaving a voicemail what crime is supposed to have been committed?)
Maria knows she is being set up but when she finds her scissors with blood on them she gets Aidan to hide them even though she knows she's done nothing wrong. And on realising Caz has been in the flat she stays there and doesn't change the locks. She eats the food in her fridge too, though there's every chance it was tampered with.
No one believes Maria, even though this is Caz, who faked an injury and her reason for leaving the army for months.
No one seems to have mentioned to the police that Caz tried it on with Maria and was knocked back and has an equal reason to fake all this than Maria would have for murdering her.
Maria 'confessed' the Pablo situation to the police who could easily have worked it out by checking the council tax register. Other people knew including her ex fiancé!
Caz now goes to and from Marias flat, walking past her place of work in daylight and is never seen. Must be all that army training!
If Caz has a flat locally and yet she is missing, has no one spotted her? No appeals by the police? Does Caz only eat takeaway whilst counting her pots of cash she seems to suddenly have - it has to be cash otherwise the police would see activity on her bank account. And not to mention the fake ID for the flat.
No wonde Maria has no faith in the plod, Jack Webster could solve this one!

How is Caz receiving the signal from the camera?

Police searched Marias flat but didn't spot the camera?

Do the police really take anonymous tip offs with no evidence that seriously and would it be enough to grant them a search warrant?

This storyline is absolutely ridiculous and I'll be glad when it's over. The writers should be embarrassed

As David Platt said in Audtrey's Salon in Thursday evening's episode: "this is ridiculous!"

I agree, this storyline is littered with plot holes and thus totally ridiculous! However, if you can suspend your disbelief (like you have to with most of Corrie these days) then it'll be interesting to see just how dark things get!

The whole point of Caz stalking Maria originally was because she was homeless and desperately needed a place to stay.

Now she has mysteriously found a nice place to live and is stalking / terrorising Maria for reasons unknown.

Now we are suppose to believe that Caz was so distraught and upset that confirmed heterosexual Maria refused Caz's advances is the reason for what Caz is doing.

She evidently doesn't handle rejection too well then

This is the soap police, they're about as much use as a chocolate fireguard!!

If Aidan and Maria had any sense, they'd install their own webcam inside Maria's flat so they could catch Caz red-handed. What a useless pair they are.

But Caz would see them doing this on her webcam

I agree, this is absolutely ridiculous, and the writers do not think before they write. They just think the viewers wouldn't pick up on, or challenge certain plot lines.

By the way, does anyone know what happened to that guy Caz got to break into Maria's flat some months ago?

Kate got off lightly then....