I'm not a fan of X-10's popup ads and other aggressive marketing techniques, but there's plenty of companies APART from X-10 who make devices which use the X-10 protocol, and there's loads of other home automation stuff. There's home automation books, devices, controllers, etc. Almost anything would interest me. Beware! Don't choose anything that's 240V-only, as Canada uses 110V!
The one part of my 3D printer that has broken - still works but is awkward, would like to replace the broken plastic with the sturdier metal version. Check prices: Including the upgraded PTFE Bowden Tube is a bonus, but honestly the main point is the Aluminium (Or Aluminum [sigh]) extruder.
RTL-SDR Software Defined Radio with 2x Telescopic Antennas
Tune ALL SORTS of stuff from 500 kHz to 1.7 GHz, basically slurps up a huge chunk of the radio spectrum, straight into a laptop / pi / etc for decoding in software, at which point you can decode a whole bunch of interesting signals from the airwaves, AM/FM/TV but also all kinds of interesting digital things, aircraft, weather stations, ships, and loads of hamradio stuff.
Similar one is currently receiving my Weather Station and noseynick.net airplane tracking, but has to alternate between them, caudsing interruptions to the airplane tracking. Would be much neater if I could be receiving more than one thing at once.
Check Prices: Sometimes the SDR-Dongle and Antennas are cheaper in the bundle, sometimes separately.