Flashing lights that go from green... to red... to blue.

That's the eerie early-morning sight Edward D'Souza started noticing recently through the windows of his 7th floor unit in a Liberty Village condo tower.

It wasn't a visitor from outer space — but a big, beaming billboard at nearby BMO Field.

"It's extremely bright," D'Souza said. "And it's really bad. It changes ads every 10 seconds."

While he says the billboard goes off around midnight and doesn't start up again until around 6 a.m., the light has been bright enough to stir him before his alarm. And he's not alone. Multiple area residents in a neighbourhood Facebook group have shared stories of being awakened, or having trouble falling asleep, for the same irksome reason.

Now, they're calling on the city for a fix.

"The brightness level is much more than it used to be," said D'Souza, who emailed both the city and Coun. Joe Cressy. "Something's definitely wrong with the board."

Each time a new advertisement displays on the BMO Field billboard, it floods the surrounding area with a different coloured light. Residents just north in Liberty Village are complaining the nightly light show is keeping them awake. (CBC News)

'There are very clear guidelines'

Cressy said his team is aware of the concerns and in regular contact with Maple Leaf Sports and Entertainment (MLSE), the company that owns BMO Field, in hopes of getting a permanent solution.

"There are very clear guidelines for how light the sign can be at night," Cressy said, adding the problems with this particular billboard go back years because of malfunctioning technology.

Ted Van Vliet, manager of the Toronto Sign Unit with the city, also confirmed the sign is monitored regularly and has been found "to exceed maximum brightness in the past."

That maximum brightness level, he explained, is 300 NITS between sunset and sunrise and 5000 NITS between sunrise and sunset. (NITS measure brightness or visible light, where one nit is equal to the light that approximately one candle gives off in one square meter.)

"The sign owner at BMO Field has been charged on two separate occasions with exceeding the maximum brightness levels in the Sign Bylaw," Van Vliet continued in an emailed statement.

Speaking to CBC Toronto, MLSE spokesperson Dave Haggith said there was a technical issue with a dimmer on the billboard last weekend, leading to the recently-brighter light, but that's since been corrected.

"We want to acknowledge the neighbourhood concern... we're working to adjust the real-time monitoring of those billboards so that situation doesn't happen again," he said.