Searching for a rental house or apartment can be fun or stressful, depending on the city in which you live, but it should always be complete. It's understandable that in tight rental markets, you may have to take what you can get, but if you have the chance, checking out "bones" material like the electrical system is worth it. There's nothing worse than renting a place only to find there isn't enough power going to the bathroom outlet to power your hair dryer.
New-build homes and apartments usually offer the latest power amounts, like plenty of 20-amp circuits. But for older places and those "studios" that you suspect were DIY jobs done by the owner, it's a good idea to check out the basic wiring before you rent. Even if you have to grab the place anyway, you'll at least know what you're getting into.
The Circuit-Breaker Box
The place you see will most likely have a circuit-breaker box. Very old places may still have fuse boxes; think carefully about renting those because, while fuses are still made and are relatively easy to obtain and replace, a fuse box indicates that the wiring could be very old, potentially neglected, and, worst of all, overheating. Fuses have to be replaced with ones that carry the same amperage; if they're replaced with ones with higher amperage, says This Old House, the wiring may overheat. That can damage insulation around the wire permanently.
Back to the circuit-breaker box, though: Look inside at the switches, which should have the number of amps imprinted on each switch. If you do not see those numbers, that's a bad sign, mainly because you have no idea how much power is going to each circuit. But it's also a sign that the breakers are old and worn.
Each switch should also be labeled, especially in larger places with several circuits. You can map out circuits if they aren't labeled, but that can take time and needs to be done before you start plugging things in.
Remember that many modern appliances like newer hair dryers need a 20-amp circuit to work without tripping one of the breakers. Ensure that the numbers you see will allow you to use what you need.
Be wary of larger places that seem to have few circuits. Your kitchen needs at least two (one dedicated for the fridge), your bathroom needs one, and separate dining areas need one. Then there should be separate circuits for the living room and bedrooms. You may want to do some advanced math to figure out the power you'd need in each room, and match that to what the breakers provide.
All outlets should be grounded, preferably. Older places may have one or two outlets tucked away in corners that have holes for two prongs, but the majority should be three-pronged. Take an outlet tester with you when you look at places for rent and stick the tester in a few of the sockets. Outlet testers are inexpensive and easy to find at hardware stores. You plug them in like you would a regular plug and look at the lights that appear. The tester will have a key that explains which patterns are normal.
A non-ground-fault circuit interrupting outlets are still OK in older places (newer ones require these outlets -- the ones with those red reset buttons -- near sinks and other water sources). It's nicer if you find that the rental has been rewired to accommodate these, however.
It sounds like a lot, but it's not that hard to check out the wiring in a potential rental place. If you have questions, you can always contact an electrician to find out the latest requirements. Contact an electrician for more information and assistance.