For the latest development, see: They've cracked the curious case of the Carstairs key fobs

Key fobs that suddenly won't unlock vehicles. Cars that won't start. Alarms that go off for no reason and can't be quieted. Something mysterious is thwarting drivers outside a grocery store in the small Alberta town of Carstairs — and it's sparking all kinds of theories.

The problems have been happening for weeks in the parking lot outside the Westview Co-op grocery store in Carstairs, a town of about 4,000 about 60 kilometres north of Calgary.

A longtime employee at the dollar store right across the street from the Co-op says it's all she hears some folks talk about when they come into her store to buy a battery for their fobs — and then discover that doesn't solve the problem.

"I've been at the dollar store almost four years," Laura Strate said, with a laugh.

"It's just bizarre. People are actually scared to go to the Co-op now because they don't know if their cars are going to start."

'People are scared to go to the Co-op'

It's lighting up social media, Strate says.

"People start getting on there and saying, 'OK, I've been to the Co-op. Is anyone else having this problem?' And all of a sudden we have 160 people commenting, 'Yes, that happened to me last week,' or 'That happened to me today,'" Strate said.

"I would say it's been probably a good month where people have known there is a problem and it's not just someone that says, 'Oh, my car doesn't work at Co-op.'"

Puzzled store calls in electricians — and even federal ministry

Westview Co-operative Association Carstairs says it's taking the matter very seriously.

"I think it is frustrating," Stephen Kennedy, the store's asset protection manager, told CBC News.

"To see the level of frustration for our team and our guests is where our concern is. That's why we are taking extra steps to ensure we are driving the solution."

Electricians from J. Williams Electric in Carstairs rode to the rescue — but the mystery endured.

"We have shut down the power source in our store this past Monday night to determine that the source of the interference isn't emanating from our location," Kennedy said.

"The location is unknown so we're just waiting for followup from the ministry."

He said they're working with a team to try and figure out what's going on, including a federal government agency.

"We have partnered with neighbours, stakeholders and the Ministry of Innovation, Science and Economic Development."

The Didsbury RCMP say they've heard the rumours and had reports so are looking into it — but it's not a priority for them.

'Put your tin foil hats on'

Meanwhile Strate says people are coming up with their own theories for what's affecting the fobs.

"We joke around here in Carstairs, 'Yeah, put your tin foil hats on,'" Strate said.

People have speculated it could be a security system recently installed by the food store, a nearby Tim Hortons that opened just after Christmas, ongoing highway construction or even the demolition of an old Rona hardware building.

But they are all just theories.

"It is pretty bizarre," Strate said.

CBC News reached out to the Ministry of Innovation, Science and Economic Development for comment, but hadn't received a response by publication time.