There are a number of strange little houses across town that look abandoned and have industrial-strength steel front doors with electrical hazard signs drilled into them. My husband jokes they’re KGB safe houses. What’s the story?—Deborah Moore, Leaside

The houses (like the one pictured) do harbour dangerous occupants: Toronto Hydro electrical transformer stations. Some dating as far back as 1920, the city’s 250-odd stations convert high-voltage raw electricity into mellower currents safe for use in homes. To camouflage them in their residential environment, about half are concealed behind uninhabited buildings (outside, so the heat can be easily dissipated). But of those disguised stations, not all look domestic. In commercial areas, Hydro hides its transformers in mock office buildings, while at Yonge and Glengrove one is tucked away in a particularly classy edifice, built in the ’30s to resemble a museum. Should you wish to investigate further, remember that it’s best to conduct surveillance from the safety of a nearby sidewalk.